A computer is a machine that manipulates data according to a list of instructions.

Computers take numerous physical forms. The first devices that resemble modern computers date to the mid-20th century (around 1940 - 1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers.^[1] Modern computers are based on comparatively tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space.^[2] Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers in various forms are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices — for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys.

The ability to store and execute lists of instructions called programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks given enough time and storage capacity.

There are some of the important aspect about the computers to be learned

1.History of computing

2.How do these man made computers work

3.Main aspect of the computers ie the main parts

a.Control unit

b.ALU(Arithmetic and logic unit)

c.Control unit

d.Input and output

4.The hardware part and software part of the computers

These are the general issues of the computers to be known at the basics

Computers are showing up everywhere you look, and even in places you can't see. Computers check out your groceries, pump your gas, dispense money at the ATM, turn the heat on and off, control the way your car runs. They're everywhere! They're everywhere!

In fact, the computer is rapidly becoming, if it hasn't already gotten there, as tightly woven into the fabric of our lives as the automobile. The analogy runs quite deep.

When automobiles were new, many people said "Those smelly, loud, complicated things will never replace the horse!" And "Those things break down in just a few miles, while my faithful horse goes on and on and repairs itself!" Nowadays it's hard to imagine the world without all the variety of four-wheeled, internal combustion vehicles. How many can you name? Sedans, pickup trucks, fire engines, front-end loaders, 4-wheelers, golf carts, bulldozers, cranes, vans, dump trucks... We have an "automobile" for every purpose under heaven - and in different models and colors, too.

Do you know all these vehicles? Click the image to see the answers. So it is with computers. There are different kinds of computers for different purposes. They are just as varied in size, expense, and ability as our more familiar 4-wheeled vehicles are.

What is a computer?

A computer is an electronic device that executes the instructions in a program.

A computer has four functions:

a. accepts data	Input	The Information Processing Cycle
b. processes data	Processing
c. produces output	Output
d. stores results	Storage
In the lessons that follow we will study the parts of the computer and each of the four parts of the Information Processing Cycle.

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Some Beginning Terms

Hardware	the physical parts of the computer.
Software	the programs (instructions) that tell the computer what to do
Data	individual facts like first name, price, quantity ordered
Information	data which has been massaged into a useful form, like a complete mailing address
Default	the original settings; what will happen if you don't change anything.

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What makes a computer powerful?

	Speed	A computer can do billions of actions per second.
	Reliability	Failures are usually due to human error, one way or another. (Blush for us all!)
	Storage	A computer can keep huge amounts of data.