A computer is a machine ( mostly electronic) that is able to take information (input), do some work on or make changes to the information (process), to make new information (output). Computers have existed for much of human history. Examples of early computers are the astrolabe and the abacus.
There are four main processing steps in a computer, and they are:
inputting, outputting storage and processing. These four steps help the
computer to work.
Modern computers are very different from early computers. They are
now very powerful electronic machines that are able to do billions of
calculations per second. Most people have used a personal computer in their home or at work. Computers are useful for many different jobs where automation is useful. Some examples are controlling traffic lights, vehicle computers, security systems, washing machines and digital televisions.
A computer user can control it by a user interface. Input devices include keyboard, mouse, buttons, touch screen.
Some very new computers can also be controlled with voice commands or
hand gestures or even brain signals through electrodes implanted in the
brain or along nerves.
Computers can be designed to do almost anything with information.
Computers are used to control factories, which in the past were
controlled by humans. They are also in homes, where they are used for
things such as listening to music, reading the news, and writing.
Modern computers are electronic machines. A computer is only useful
if it has both hardware and software. Hardware is the physical parts the
computer is made of - for example keyboard, mouse, screen, tower, and
the circuits inside it. Software is the computer programs (mathematical
instructions). The software uses the hardware, when the user gives it
instructions and changing it in to useful output.
Many modern computers do billions of calculations each second. They do mathematical arithmetic very quickly but computers do not really "think". They only follow the instructions in their software programs.
Computer programs are designed or written by computer programmers. A few programmers write programs in the computer's own language called machine code. Most programs are written using a programming language like C++, Java, and Python. These programming languages are more like the language you talk and write with every day. A program called a compiler translates the user's instructions into binary code (machine code) that the computer will understand and do what is needed.