Computer Input Devices

Once upon a time, the only way one could get data into computer memory, was through a keyboard. However, with the speed of technological advancement, newer and faster devices have been created. This helps one get loads of information transferred into the computer, without having to do much manual work.

What are Computer Input Devices?

These devices are hardware components that help you transfer information into a computer. Without them, your computer will be more or less like a television set. So an input device is any peripheral device that helps feed data and control signals to a computer. These devices can be broadly classified, according to the modality of input, discrete/continuous input, and the degrees of freedom involved. Some are classified according to their pointing ability, as follows:

  • Direct input devices, where the pointing is done directly in the space where the cursor is seen. Examples are touchscreen pointers and light pens.
  • Indirect pointer examples are a trackball or mouse.
  • Pointers for touchscreen, where the positional information is absolute or relative, when the mouse is lifted and positioned according to need.

List of Input Devices

These devices help in manipulating data on a computer. The following are some of the most commonly used input devices.

Keyboard: The oldest and most widely-used computer input device is the keyboard. It is available with desktop computers, laptops, etc. The computer keyboard contains all the alphabetical and numerical keys for input of data and commands. The keyboard is generally connected to the computer with a wire, but nowadays, wireless keyboards are also very common.

Mouse: The small hand-held computer device that helps make selection and navigation of the screen easy, is the mouse. The mouse displays a cursor on the screen that serves as a guide for opening files and folders, as well as making selections. The mouse, like the keyboard, is either connected with the computer through a wire, or has a wireless connection.

Stylus: The tablet uses a pen-like computer input device known as a stylus. This helps one write on tablets or touchscreens like a pen. Some tablets and styluses have buttons, that make their usage as a mouse possible. Many latest tablet models allow the user to use their fingers, instead of a stylus.

Joysticks: If you are an ardent fan of gaming, then you may be aware of what a joystick is. This is a movable stick with a button or two, that helps one control the movements of characters in a game. Many latest joystick models come with different buttons to help you make complex movements, with just a push of your fingers.

Scanners: Scanners help you make virtual photocopies of your documents or even a photograph. You can copy a digital image of the document you wish to copy, and save it on the computer, or take prints. This copy can be edited by running a graphics program.

Headsets: Headset devices have an earphone, as well as a microphone. This helps you record your voice, dictate data, or even send commands to the computer. Some headsets help you keep your hands free for working on different tasks. You can even add voice recognition software, so that only your voice will be accepted by the computer to dictate commands.


There are different devices that help you share information with your computer in different formats. The following are a few examples that help you digitize images and videos, from other devices, into your computer.

Video Input Devices

  • Web cam
  • Image scanner
  • Digital camera
  • Barcode reader
  • Fingerprint scanner
  • 3D scanner
  • Laser rangefinder
  • Video capture hardware
  • MIDI Keyboard

Medical Imaging Devices

  • Magnetic Resonance Imaging (MRI)
  • Computerized Tomography (CAT Scan)
  • Positron emission tomography
  • Ultrasonography

These are some of the devices that help you store data from other devices into your computer. Technology continues to come up with more advanced modes of data transfer, as computing becomes an integral part of our lives.

Difference between Software and Computer Hardware

While computer jargon can be hard to get to grips with, two terms that pop up extremely often in any computer discussion are the words “software” and “hardware”.

But what is the difference about computer software and hardware?

These two terms refer to the most fundamental parts of computer systems. Both of them are vital for any computer to operate, and they are also dependent on one another.

Definition of Computer Hardware and Software

When we talk about computer hardware, we mean the actual components of your computer. Such things as the computer’s motherboard, its CPU, the video card, the keyboard and mouse, these are all “hardware”.

The difference between computer software and hardware is that software refers to the coding and various programs that you have on your computer. These include your operating system (Windows etc), media players, Photoshop etc.


Computer hardware is usually multi-purpose in that it is able to perform lots of different tasks. For instance, your computer monitor doesn’t just display images on screen; it also shows videos, widgets and text. One difference between computer software and hardware is that software is normally only designed to perform one task.

Your media player for example, is only for accessing media like movies and songs. It cannot edit photos or browse the web. The only real exception to this is the operating system itself, which is a user-friendly interface designed to let you access all the other bits of software and files stored on your PC.

System Requirements

Computer software can only function on a computer if that computer meets the system requirements needed to run it properly. Such requirements include hard drive requirements, a minimum processor speed, RAM requirements and a supported operating system.

Occasionally a piece of software will have additional requirements, and these will normally be printed on the box when you purchase it, or else it will be displayed on the website you have downloaded it from.

Bit Rate 64 Bit vs 32 Bit

The transition in computers from operating systems of 32-bits to operating systems of 64-bits has become a recent issue with hardware and software. The difference between the two kinds of operating system are that 64-bit systems can access more RAM and are able to process much bigger data chunks than the old 32-bit systems.

In order to run software that is 64-bit, it is necessary to have a 64-bit CPU along with a motherboard that is compatible with the software. Because there are many computers that don’’t have the hardware necessary to run the 64-bit versions of software, many manufacturers release both 64-bit and 32-bit versions of their programs.


Both computer software and computer hardware are being constantly developed, with superior components and programs being released all the time. The development of hardware is usually focused on creating faster and more compact components through the use of new technology.

Meanwhile, developers of software are constantly striving to keep pace with these new advancements in hardware by building smoother running, better looking and more comprehensive programs. The result of this is that computer users are constantly being required to update their hardware to be able to run the latest pieces of software.

Computer Hardware Engineering

In simple words, computer hardware engineers are people, who take care of all computer hardware maintenance, they are assigned to. To enter this field, one obligatorily needs to have strong technical knowledge of computers. A software computer engineer may not know much about computer hardware, but a computer hardware engineer is well aware of how software works. This knowledge helps him solve hardware problems more efficiently and responsively.

Professionals in this field are responsible for carrying out research, contriving, participating in the development, and examining the installation, troubleshooting, and maintenance of all computer hardware. They are directly related to the care and maintenance of computer chips, motherboards, network components and devices, servers, databases, keyboards, modems, printers, scanners, and many more computer peripherals. The speedy advancements in information technology are predominately the outcomes of hardworking efforts made by these professionals.

Due to a rapid change in several technologies, computer hardware engineers are required to update their knowledge base accordingly, so that they can provide every possible service to their clients and customers. In this regards, they are offered technical trainings by companies which they work in. Companies also allow continuing technical education to upgrade their knowledge and skills. This all is done because the company needs their engineers to use their skills and provide maximum services, which may in turn have a good effect on other employees’ performance in the company.

The number of these engineers working at present is lower in comparison to other professionals in the IT field. According to a survey conducted in 2002, they collectively hold approximately 74,000 positions. Out of them, 40% engineers were operating in computer and electronics facilities, whereas 1/4th were providing their services in ‘scientific’ and ‘technical service’ companies that were associated to the IT industry. Others were catering to technical needs of several telecommunication giants. Nowadays, computer hardware engineers might have to pass through tough competition, as the number of degrees granted in the information technology sector has increased enormously. The job advancements principally depend on the years of experience in the same field along with required qualifications. If you desire to get into a computer hardware career, you are required to at least own a bachelor’s degree in the engineering field.

A prospective hardware engineer should also have a liking towards work and learning new technologies. Computer hardware engineers should have the capability of troubleshooting and finding potential problems as soon as possible to preclude severe loss in deliverables. Their working time is never fixed and may change according to the requirements of their services. They may be called upon by their respective employers in case of a technical problem in the server or database, which would be causing a problem to the company employees in carrying out their duties. Hardware engineers are required to have perceivable oral and acceptable written communication skills, to communicate with affected users, so as to interpret what issues they actually face. The main attraction in this profession is the pay scale. Referring to the salary survey stats of 2006, these engineers earned a handsome salary which was around $70,000 to $110,000 per annum.

With a rapid increase in the use of information technology among several industries around the globe, there is certainly a high possibility of an increase in the job opportunities of computer hardware engineers.

What is the Processor Cache

Main memory is a computer device with the slowest access rate. If the CPU needs a data item, a request is sent to the main memory via a memory bus. The main memory then searches for the data item and sends it back to the CPU. Lot of time is wasted in this entire cycle. What if the data item were stored somewhere close to the CPU? The working of processor cache is based on a similar concept. To understand the concept of cache memory, we will take an example of a library throughout this article.

Suppose, we have a library, with a single librarian. If a person comes and asks for Harry Potter Part I, then the librarian goes to the bookshelf and retrieves the book and gives it to the person. When the person is done with the book, it is restored to the shelf. If, any other person comes and asks for the same book, the cycle is repeated again. This is exactly how a system works without a cache memory.

Why do we need processor cache?
Now, let’s see what happens in the presence of a cache memory. In our library example, let’s consider a drawer at the librarian’s desk as a cache. The procedure remains the same, when the first person places a request for a book. But, when the book is returned, the librarian does not store it on the shelf, instead keeps it in her drawer. Now, when the next person comes and places a request for the same book, the librarian simply has to retrieve it from her drawer. In a similar way, cache memory stores the data items that are frequently required by the processor. Thus, every time, the data is requested, processor simply looks in the cache and retrieves it, saving a long trip to the main memory. This tremendously increases the processor speed.

Does cache memory store only the frequently used data items?
No, cache memory is a smart piece of memory that also looks for the data that is likely to be requested in the near future. Continuing with our library example; when the person requests for Harry Potter Part I, our intelligent librarian also fetches Harry Potter Part II along with it. Now, when the person is done with the first book, it is very likely that he might ask for the second part. And when he does, librarian has it ready in her drawer. Similarly, when the cache memory fetches data items from the main memory, it also fetches the items that are located at the addresses near the requested items. These adjacently located chunks of data which are transferred to the cache is called the cache line.

Two-level processor cache
Most hard drives and other components make use of a single-level cache. But a processor cache is a two-level cache, in which level 1 cache (L1) is smaller and faster; while level 2 cache (L2) is slightly slower, but anytime faster than the main memory. L1 cache is divided into two parts viz., instruction cache and data cache. Instruction cache stores the set of instructions that are required by the CPU for computing; while the data cache stores the values that are required for current execution. L2 cache is responsible for loading the data from the main memory. Again, coming back to our library example, consider a librarian’s drawer as L1 cache. On any busy day, when the demand for books is high and the librarian has already stored many books in her drawer, chances are that it might get full pretty quickly. This is where L2 cache comes into the picture. Consider a bookcase near the librarian’s desk as L2 cache. When the drawer fills up, the librarian starts storing the books in the bookcase. Now, whenever there is a demand for some popular book, the librarian first looks in her drawer; if the book is not found there, she searches it in the bookcase. Similarly, when L1 cache is full, data is stored in L2 cache. The processor first looks for the data in L1 cache, and if it is not found, then only L2 is searched. If the data is not found in L2 as well, a trip to main memory is inevitable.

Is implementing more cache a good idea?
Yes and No. Implementing more cache will let you fetch data quickly, only in the cases, when the data is available in either L1 or L2. Coming back to our library example. If a person requests a popular book, which is not stored in the librarian’s drawer or the bookcase; she first looks for it in the drawer and then in the bookcase. This way, lot of time is wasted before she finally retrieves it from the bookshelf. Similarly, the processor checks first in L1 and then, in L2, and when the item is not found in either cache, then only sends a request to the main memory. As you must have realized, lot of processor time is wasted, in looking for the item in the two cache memories. When the processor finds the required data item in any of the cache memories, ‘cache hit’ is said to have occurred; on other occasions, a ‘cache miss’ takes place. Data items are periodically updated and replaced using various algorithms to maximize the instances of cache hit.

One might think that if cache memory is so fast, why not implement it large enough so as to store entire data of the main memory in it? The reason, is that, although cache memory offers fast access, the speed comes at a great expense. Hence, proper utilization of the available cache memory is must.

Learn about computer hardware

This was the way I learned about computer hardware. In Sydney, Australia where I live we have a council cleanup. During this time, everyone puts out rubbish and their junk onto the side of the road for the council to pick up on a certain date. Included in this rubbish were computers, lots of computers. So when this council cleanup was in my area, I would jump on my bike (often with some of my brothers) and ride around looking at the junk piles.

I started to collect computers and have a look inside them. I was really interested in how these complicated machines worked. Then I started to fiddle with some of the components and learn what each one did. I wanted to upgrade my computer so I tried adding a hard drive. I didn’t know how so I searched Google or got a book from the library.

After successfully doing this, I thought that my CPU (central processing unit) was a bit slow, so I tried to change that. Now this was my embarrassing moment and one that I look back on and laugh. Now in my family we have many computers. Mum had just bought a new computer so I received her last one. She hadn’t taken any information of it yet, so she didn’t want it to break. Well her computer that she gave me had an AMD, 700MHz chip and I found in my searching through junk, an Intel 1GHz Pentium III.

I didn’t really understand computer hardware so I thought that you could just swap any CPU. So I took Mum’s AMD chip out and then tried to squeeze my Pentium III chip in its place. Of course it didn’t fit, since an Intel chip can’t go in an AMD motherboard. However, this didn’t stop me. I started to bend the pins on the Intel chip so that it would fit in the AMD motherboard and eventually it did. I turned it on and then smelt something burning and then I saw something burning.

I had completely blown up everything in the computer. My mum wasn’t happy as she lost her information and my computer (my first computer) didn’t work anymore. What a learning experience!

How to Update Computer BIOS with Easy

BIOS stands for Basic Input/Output System, and it is typically a software that is embedded on the motherboard of a system. It controls the hardware such as disk drives, keyboard, mouse, display settings, pen drive etc., that are attached to it, and sends the information to the Operating System (OS) of a computer. Motherboard is the center of coordination in a computer that unites the hardware of the system and enables communication between each other. Any upgrades that are required in a computer depends on the type of the motherboard and its inbuilt features.

What is Computer’s BIOS?

The computer’s BIOS is basically an EEPROM, which stands for Electrically Erasable Programmable Read-Only Memory. EEPROM is a non-volatile memory which means that, the information which is stored can be retained later even when it is not powered. EEPROM can be modified by the user, and can be erased and reprogrammed. Most of its components are not serviceable, as it is soldered to the motherboard. The firmware i.e., the coded instruction in the BIOS can be updated or upgraded. In modern computers, it is inbuilt on a chip called CMOS, which stands for ‘complementary metal oxide semiconductor’. The common type of EEPROM is flash memory which is electrically erasable, that exists in CMOS chips. Such type of CMOS chips can be updated to a newer version. Most of the Intel Core Pentium computers and 486 PCs use CMOS chips, which can be easily updated.

Updating BIOS of Your Computer

Step #1: This is a very important step which you must know. You cannot decide on which type of update you want. Look for your system information on your computer and note the BIOS version number. There are two ways to find its version.

  1. From the system information screen of your computer, the route to view this screen is: Start → Programs → Accessories → System Tools → System Information.
  2. One way is through the command prompt. Enter the command systeminfo on the run box or on the box that appears after you click on the start button.

There are various companies that manufacture the computer’s motherboard. Some of the leading motherboard companies are listed below:

  • Acer
  • Abit
  • Albatron
  • AOpen
  • Biostar
  • DFI
  • Elitegroup Computer Systems (ECS)
  • First International Computer (FIC)
  • EVGA
  • Foxconn
  • Gigabyte
  • MSI
  • Intel
  • Zotac
  • Supermicro
  • Tyan

Step #2: After identifying the motherboard information and your computer’s BIOS version, go to the motherboard manufacturer’s site and check out for the BIOS update files and download the correct update file. USB thumb drives containing the required files, can also be used instead of downloading files from the Internet. For example, we will take Intel desktops, in which we have various update files such as:

  • Express BIOS
  • F7 BIOS Flash
  • iFlash BIOS
  • ISO Image BIOS
  • Recovery BIOS
  • Integrator Toolkit BIOS

Step #3: After downloading the required BIOS files, reboot the system and check whether the files are uploaded properly. Some systems automatically reboot after the download, and if your system doesn’t reboot by itself, it is advisable to restart it yourself.

  • Identify the right BIOS version number. If you are not able to find it by yourself, ask for help or directly contact the motherboard manufacturer.
  • Choose the correct BIOS update file from the motherboard manufacturer’s site.
  • If you are downloading the BIOS update file from the CD provided by your motherboard manufacturer, ensure that it is not an outdated version.
  • Properly understand the instructions given in the manufacturer’s site, before you start downloading the BIOS update files.
  • Do the update where there is an uninterrupted power supply in order to avoid failure in the updating process.

Update you computer’s BIOS only if it is necessary. It is advisable to upgrade the files using USB rather than doing it online from the Internet. By doing this, you can minimize the risk.

How to Upgrade Graphics Card

The graphics card is also known as video card, graphic controller, graphics accelerator or display card. It is a PCB (printed circuit board) that has three major components. These components are video memory, video BIOS, and graphics processing unit.

The graphics card should be changed if it gives a poor performance or if you want more speed options for the computer games. In the first case, you need to verify that it is the reason for the poor performance and not the computer. To do this, use the scan disk or defragmentation options and look for bad sectors on the hard disk. You can also try using other ways to speedup your computer. If they do not work, you can conclude that the lowered performance is due to the faulty working of the card. Once it has been established that the graphics card is responsible for the low speed, you should upgrade it.

Some video cards are integrated in the motherboard and some are externally connected to the computer. Older versions of motherboards used a PCI (peripheral computer Interconnect) slot in order to plug-in the video card. Newer versions of computers use the accelerated graphics port (AGP). The latest version of computers use the PCIexpress, which has a speed twice of the AGP slots.

The task of upgrading the graphics card in your desktop computer, involves finding out the type of slot in your computer motherboard. If your computer system is relatively quite old, then it is likely that it has a PCI slot. In this case, you have to upgrade related hardware in your computer system, as well. This is because, nowadays, graphic cards compatible only with PCIexpress are available. Additionally, they also render high-speed outputs.

The power supply required for a graphics card should also be considered before buying one. The power supply or wattage of the computer must be checked. The power supply ratings range from 350-500W. Also, the available computer RAM must be taken into consideration. Minimum RAM of 512 MB is required. Once all these steps are done, you can buy a new video card. Make sure that you compare all the options available in the market, and choose the one that best suits your needs.

To remove the older one and upgrade the computer hardware to a new video card, follow the steps given below:

  • If you already have a graphics card, un-install the drivers of the same. Download the drivers of the new one that you’ve purchased and store them on your computer system.
  • Remove the overclocks, usually set to increase the performance of your computer by increasing the clock rate. Set the computer system to its original specifications and turn it off.
  • The power cord should be unplugged. Open the cabinet and search for your PCIexpress slot. The PCIexpress slot has a locking clip, which is used to mount the card. Remove the older card and mount the newer one. Store the older card in an anti-static bag, as you can use it as a back-up.
  • The computer system can then be switched on, after carefully placing the graphics card in its slot. Start your computer and install the drivers which were downloaded earlier. This ends the up-gradation process and you can start playing games.

The graphics card is basically used to ensure performance, drive a digital screen, and support dual screens for playing games.

Ways Computers Work

So how do computers work?

Have you ever just looked at a computer and go “how does that work”?  If you think about it, computers are quite amazing.  You press a few buttons and you can talk to your friend over the other side of the world, you can learn anything you want on the internet, you can listen to music, watch TV, write stories, make videos and do much much more.

The more you think about it the more amazing it is and the more crazy it is that a bunch of computer bits can do this.  So how do computers work?

Well I will try and answer this the best that I can.  Basically a computer can consist of two broad categories, hardware and software and the way a computer works is between these two working together. I will oultine them both briefly below.

Computer Hardware

If you have been reading any of this website, then you probably already understand what computer hardware is, because that is what this website is about. Like seriously,

So briefly: computer hardware is the physical computer that you actually see, this includes: the computer, monitor, keyboard, mouse, printer, speakers etc.  Inside the computer is more hardware, such as the hard drive, CPU (central processing unit), motherboard, RAM (random access memory) and more.

How to Open Computer BIOS Setup

What happens when you turn on your PC? Lights come on the keyboard and monitor, the computer’s brand logo may appear on the screen, then the operating system loading message appears. This is all occurring on screen, but in the background, your computer is actually powering on and preparing its external and internal parts. Many assume the Operating System (OS) is the first program a computer loads and operates on but the actual start-up program is the BIOS.

BIOS stands for Basic Input/Output System, which is inbuilt in every PC during manufacturing and is loaded, run and executed when you press the power ON button of your PC. The BIOS is a sort of firmware interface for a computer. Different components, such as pen drives, graphics card, keyboard and mouse and disc drives attached to a computer, need to be initialized and identified to the computer. The BIOS does this in the form of a check-list (“turn USB ports on”, done) and this procedure is known as POST (power-on self-test). The operating system itself is a program, which needs to be loaded and executed. This too is performed by the BIOS, which locates the OS program on the computer’s hard disk and runs the program. One needs to enter the BIOS interface to change various system-level settings, such as changing the system clock, changing the boot up drive and managing memory. Listed below are the steps on how to access the computer’s BIOS setup.

How to Get Into Your Computer’s BIOS?

Step 1: Start your PC or restart it. When the computer starts up, usually the manufacturer’s logo or the brand name of the PC is displayed on a black screen. In some cases, the screen turns into the logo of the operating system and a “loading” or “starting” message appears on the screen. At such booting screens, a small message is displayed, which has the combination of access keys needed to enter the BIOS. Examples of such messages are:

  • Press “key” to enter BIOS
  • “key” = Setup
  • To enter the BIOS setup, press “key” + “key”
  • Press “key” to access system configuration
  • Press “key” to enter the Setup menu

In some computers, the manufacturer’s logo or brand name shows up and no message for entering the browser occurs. So try pressing the Tab or the Esc key to remove it. You can either note the key down or if the screen changes too fast for you to enter the BIOS, press the Pause/Break key on your keyboard. This key will pause the booting screen, so you can understand which keys are needed to access the BIOS. To unpause such a screen, press any key.

Step 2: Once you know the access key combinations, then press that key or press the combination of keys during the booting screen to enter the BIOS interface. In some computers, just one press of the key is enough, with others, you may need to tap it repeatedly. Do not press and hold down the key with force or press it too many times. The system may hang or an error code will show up on screen and you will need to restart your PC. With certain machines, pressing the DEL key repeatedly at the boot up screen, before the OS loading screen appears, can bring up the BIOS screen. Other common BIOS keys are F1, F2, F10, F12 and ESC.

Step 3: The BIOS is not dependent in any way on the operating system. So whether you are running Windows 7 or Mac OS X, the OS has nothing to do with your BIOS and hence different operating systems does not mean different BIOS access keys. Instead, your computer’s BIOS depends on the manufacturer of the motherboard, like Acer or ASUS. So there are proprietary access keys to enter the BIOS screen, based on the brand of the computer. Some computer systems and their BIOS access shortcuts are:


  • Acer
  • Compaq
  • Dell 400
  • Dell 4400
  • Dell Inspiron
  • Dell Latitude
  • Gateway 2000
  • Hewlett-Packard (HP)
  • IBM
  • Micron
  • Packard Bell
  • Sharp
  • Sony VAIO
  • Toshiba 335CDS
  • Toshiba Portégé
  • Toshiba Satellite
  • Toshiba

Access Keys

  • F1, F2, CTRL+ALT+ESC
  • F10 (newer), F1, F2, DEL (older models)
  • F3, F1
  • F12
  • F2
  • Fn+F1, Fn+ESC
  • F1
  • F1, F2, ESC (for laptops)
  • F1, F2 (E-pro laptop)
  • F1, F2, DEL
  • F1, F2, DEL
  • F2
  • F2
  • ESC
  • ESC
  • F1
  • Tecra F1 or ESC

Warning: The above-mentioned access keys may differ from computer to computer, so always verify the information prior to usage. The correct access keys are provided as a part of the computer’s documentation. This site does not assume any responsibility for any issues that could occur by using the above information.

The BIOS is a rather sensitive part of your computer’s internal makeup, so pressing a lot of keys at the boot up screen is not a good idea, unless you know what you are doing. So do not press any or all keys in tandem or with force to enter your computer’s BIOS. Instead, refer to your computer’s manual and look for System Settings or similar headings to find the correct BIOS key. You can even search online using your computer’s model number and make.

Once you have actually accessed the BIOS and are facing the lovely light blue screen, here’s a word of caution; fiddling with BIOS settings is not for novices or the ill-informed. If you know what you are doing, then only change settings and to be safe, write down what you are changing, in case you need to go back and re-change it. Use the arrow keys and function keys to navigate and select options within the menu. Accessing the BIOS of a computer’s system can be done to change certain basic computer settings and workings, but should be carried out with caution.

Types of Networking Devices

A computer network is not made up of one machine or even one type of machine. It is a carefully designed system of different hardware components (networking devices) working in tandem with various rules and communication protocols. From the network scenario in a household, to a medium scale network in a school or mall to a large, border-crossing network of a corporation or service, a computer network is made up of various hardware parts, some standard and some rare and more complex. So, what are the different types of network hardware? Read on for a listing of such devices and a brief explanation of each.

Types of Network Hardware

Cables & Wires
Everything may be turning wireless nowadays but at least 2-3 wired connections have to exist somewhere in a computer network. Connecting a desktop to a router or the router to the modem, such connections are always wired and the common cable type used is CAT5 RJ-45. Wiring is typically thought of as being a Layer 1 (physical layer) device as raw data or signals are transferred from one end to the other.

Network interface cards is easily one of the most important components of a computer network. It is a hardware part that allows the computer to be identified amongst others in a network and allows the computer to connect to a network. It works in the physical and data link layer of the OSI model. This card provides the circuitry required to implement a networking standard. The most common NIC form used is Ethernet. Recent computers, both desktops and laptops have their NIC built on the motherboard, earlier computers needed an internal or external NIC to be added. Laptops with built-in Wi-Fi have wired and wireless NIC capability, but most desktops have only wired connection capabilities and will require a wireless adapter to connect wirelessly.

Connecting more than one computer to a higher layer networking device like a router can be difficult, if you do not have a hub. A hub collects various devices through a wired connection and groups them into a segment. So, the network recognizes all devices connected to the hub, as one segment. Typical hubs allow Ethernet wired connections and have at least 4-5 ports on them and can have 8, 12 or even more ports. They are very simple devices, they do not manage or filter or function in any other manner, other than to act as a collection point. They operate in the physical layer of the OSI model.

A modem acts as a sort of converter or translator. It allows digital data or information to be transmitted over traditionally analog lines of transmission such as a telephone line. The word “modem” is a mix of two transmission terms, “modulate” and “demodulate”, which are the two main operations performed. The digital signal from a computer is converted into analog form, sent over the analog medium and then decoded back into its digital form at the receiving end.

Routers can be thought of as the mailroom of a network. They receive incoming data packets, decipher their addressing information (where did they come from, where do they have to go) and send them accordingly. Routers are essentially used for traffic management. They function in Layer 3 (network layer) of the OSI model. Routers are much smarter than hubs, they can implement security protocols, assign IP addresses, both static and dynamic and can function in both the wired and wireless transmission band. There are different router types based on their area of use, such as home or small-use routers to enterprise routers, which are used for complex routing functions in large corporations.

A gateway acts as the meeting point or go between point between 2 different networks, using different protocols. e.g. Network A uses one protocol, Network B uses another. A computer from A wants to communicate with a machine from B but due to the difference in protocols, it does not know how to communicate. It can adopt or add B’s protocol but this is a tasking process and is not really efficient. Instead, a gateway will translate the request from the computer in A’s network, into B’s language and then translate the reply from B’s language into A’s. So, the 2 machines can communicate without any change in protocol. Gateways function in all layers of the OSI model, since they perform conversion or translation functions.

Wireless Access Points
An access point acts as a middle station for a network and helps in adding more users to it. They are connected to the network but act as a transmitter and receiver for the network signals, so other devices can connect to the access point and in turn will be connected to the main network. The best example for an access point scenario is a large house, where the router is located in the basement. So, the ground floor can receive the wireless signal but the first floor cannot, due to the network’s limited range. An access point connected on the ground floor will receive the router’s wireless signal and emit it to reach the first floor, enabling users on that floor to access the original network.

With advances in technology, the features and specifications of such devices may change or the device itself may become obsolete. But for now, this collection of network hardware remains constant; and at least one or two of the above devices can be found in any computer network.