The main functions of a computer is to process and store data.
In the past computers’ size were very big like room. And they were consuming so much power as you can guess. Nowadays size is up to you. You can use your phone which is very small, or buy a workstation which is like desktop.
First computer is introduced in 1948.
First computers were mechanical. Even if you think that if computer is a device that lets you calculate faster, then even an abacus is a computer.
In the past “computer” was a person doing the calculation job with a calculator. Now the devices took that name.
First computer programmer is Augusta Ada Lovelace. In 1979 the computer programming language ADA is introduced. Name is coming from first programmer. ?
First general purpose computer is ENIAC. At the same time it is the first computer that uses Neumann architecture.
Neumann architecture is simply a computer architecture that data and commands are kept together at the same storage unit. This term is used for every machine that uses Turing machine principles.
Turing machine is a simple calculator first introduced by mathematician Allan Turing in his study On computable numbers, with an application to the Entscheidungsproblem. You can see the original from here; http://www.turingarchive.org/browse.php/B/12]