Computer Network

A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections. The connections (network links) between nodes are established using either cable media or wireless media. The best-known computer network is the Internet.

Network computer devices that originate, route and terminate the data are called network nodes.^[1] Nodes can include hosts such as servers and personal computers, as well as networking hardware. Two devices are said to be networked when a device is able to exchange information with another device.

Computer networks support applications such as access to the World Wide Web, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications. Computer networks differ in the physical media used to transmit their signals, the communications protocols to organize network traffic, the network's size, topology and organizational intent.

For beginning computer users, the computer aisles at an electronics store can be quite a mystery, not to mention overwhelming. However, computers really aren't that mysterious. All types of computers consist of two basic parts:

• Hardware is any part of your computer that has a physical structure, such as the computer monitor or keyboard.
• Software is any set of instructions that tells the hardware what to do. It is what guides the hardware and tells it how to accomplish each task. Some examples of software are web browsers, games, and word processors such as Microsoft Word.

A motherboard (hardware)

Microsoft Word (software)

Anything you buy for your computer can be classified as either hardware or software. Once you learn more about these items, computers are actually very straightforward.

The first electronic computer, the Electronic Numerical Integrator and Computer (ENIAC), was developed in 1946. It took up 1,800 square feet and weighed 30 tons.

To make a computer do anything, you have to write a computer program. To write a computer program, you have to tell the computer, step by step, exactly what you want it to do. The computer then "executes" the program, following each step mechanically, to accomplish the end goal.

When you are telling the computer what to do, you also get to choose how it's going to do it. That's wherecomputer algorithms come in. The algorithm is the basic technique used to get the job done. Let's follow an example to help get an understanding of the algorithm concept.

Let's say that you have a friend arriving at the airport, and your friend needs to get from the airport to your house. Here are four different algorithms that you might give your friend for getting to your home:

The taxi algorithm:

1. Go to the taxi stand.
2. Get in a taxi.
3. Give the driver my address.

The call-me algorithm:

1. When your plane arrives, call my cell phone.
2. Meet me outside baggage claim.

The rent-a-car algorithm:

1. Take the shuttle to the rental car place.
2. Rent a car.
3. Follow the directions to get to my house.

The bus algorithm:

1. Outside baggage claim, catch bus number 70.
2. Transfer to bus 14 on Main Street.
3. Get off on Elm street.
4. Walk two blocks north to my house.

All four of these algorithms accomplish exactly the same goal, but each algorithm does it in completely different way. Each algorithm also has a different cost and a different travel time. Taking a taxi, for example, is probably the fastest way, but also the most expensive. Taking the bus is definitely less expensive, but a whole lot slower. You choose the algorithm based on the circumstances.

In computer programming, there are often many different ways -- algorithms -- to accomplish any given task. Each algorithm has advantages and disadvantages in different situations. Sorting is one place where a lot of research has been done, because computers spend a lot of time sorting lists. Here are five different algorithms that are used in sorting:

• Bin sort
• Merge sort
• Bubble sort
• Shell sort
• Quicksort

If you have a million integer values between 1 and 10 and you need to sort them, the bin sort is the right algorithm to use. If you have a million book titles, the quicksort might be the best algorithm. By knowing the strengths and weaknesses of the different algorithms, you pick the best one for the task at hand.

What is Computer : Computer is an electronic device that is designed to work with Information.The termcomputer is derived from the Latin term‘computare’, this means to calculate.Computer can not do anything without a Program.it represents the decimal numbers through a string of binary digits. The Word 'Computer'usually refers to the CenterProcessor Unit plus Internal memory.

Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations.The basic components of a modern digital computer are: Input Device,Output Device,Central Processor. A Typical modern computer uses LSI Chips.

Charles Babbage is called the "Grand Father" of the computer.The First mechanical computer designed by charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards.

Four Functions about computer are:

accepts data	Input
processes data	Processing
produces output	Output
stores results	Storage

Input (Data):

Input is the raw information entered into a computer from the input devices. It is the collection of letters, numbers, images etc.

Process:

Process is the operation of data as per given instruction. It is totally internal process of the computer system.

Output:

Output is the processed data given by computer after data processing. Output is also called as Result. We can save these results in the storage devices for the future use.