What is a computer?

“I think it’s fair to say that personal computers have become the most empowering tool we’ve ever created. They’re tools of communication, they’re tools of creativity, and they can be shaped by their user.”

Bill Gates

Modern world is impossible without computers and their applications. They are almost in every sphere of our life. But what is a computer? While the term computer can apply to virtually any device that has a microprocessor in it, most people think of a computer as a device that receives input from the user through a mouse or keyboard, processes it and displays the result on a screen.

The first electronic digital computers (developed between 1940 and 1945) were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space.

A computer is an electronic device that accepts, processes, stores and outputs information. A typical computer system consists of two parts: hardware and software. Hardware is any electronic or mechanical part you can see and touch. Software is a set of instructions, called a program, which tells the computer what to do.

All general-purpose computers require the following hardware components:

- memory: enables a computer to store, at least temporarily, data and programs.

- mass storage device: allows a computer to permanently retain large amounts of data. Common mass storage devices include disk drives and tape drives.

- input device: usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.

- output device: a display screen, printer, or other device that lets you see what the computer has accomplished.

- central processing unit (CPU): the heart of the computer, this is the component that actually executes instructions.

There are physical units attached to the computer (e.g. the keyboard, the monitor, etc.). They are called peripherals. At the back of the computer there are ports into which we plug external devices (e.g. a scanner, a modem, etc.). They allow communication between the computer and the devices. In addition to these components there are many others that make it possible for the basic components to work together efficiently.

Personal computers in their various forms are what most people think of as “computers.” However, the embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are the most numerous.

Computers help to diagnose diseases. They are the best means for storage and management of data. There are fully automated factories running on software. We book air tickets or railway tickets using the Internet. We make hotel reservations online.

Shopping via Internet is common nowadays.

Nowadays millions of people can no longer live without computers.