Theory:

Being in a modern-day, you must have handled, viewed, or known about computers, because they are an integral part of our day-to-day lives. Be it school, banks, shops, railway stations, hospital or your own home, computers are present everywhere, making our work easier and faster for us. As they are such integral parts of our lives, we must know what they are and how they function. Let us start with defining the term computer formally.

The meaning of computer is a device that can calculate. However, modern computers can do a lot more than just calculating.
 
The computer is an electronic device that receives input (data / information), stores or processes the input as per user instructions and provides output in the desired format.
We can save the data and translate it into information. We can use the computer in many ways. 
 
8c906cfdebfd962edfe2a635c08bb0fc.jpg
A computer is referred to as a system because it consists of integrated components (input, output, storage and CPU) that work together to perform specific tasks called for in the program being executed.
Functions of a computer:
Basically, a computer performs five basic operations. These includes
  • Input or inserting data and instructions.
  • Storing data or information in its memory and retrieving them whenever it is necessary.
  • Processing the data and converting them into useful information.
  • Generating the output or retrieving the data or information.
  • Controlling of devices and functions.
Applications of a computer:
Since the computer's invention, they have grown in terms of increased computing power, and at the same time, their size has been reduced. Due to the widespread use of computers in every field, modern life would be impossible without them. Human lives have been made better and happier by computers.
 
Computers are used in various fields of work.
  • Engineers, architects, jewellers, and filmmakers all use computers to design things.
  • Teachers, writers, and most workers in-office use computers for research, word processing and information transaction (E-mail).
  • Computers are used in small businesses as a point of sale and for general record keeping.
  • Computers are used in banks for Online accounting facilities and ATM's.
  • Airports and Railways use computers to book tickets. They also use them to maintain timings.
  • Computers are used in Post offices in order to save various kinds of official data such as photocopy of letters received from headquarters, records of the number of letters received in a given time of period, keeping the records of accounts opened in post offices.