4000 years ago
People were using a wooden rack that had rods mounted with beads on them.
For performing arithmetic calculation peoples were using to move to bead by the abacus operator according to few rules.
Abacus is still used in countries like China, Russia, and Japan
Below are the image for the reference of abacus
The abacus is known as a digital device; That represents values discretely.
A bead is a predefined position or another that shows the value either one or zero.
As we know the computer by the 19th century that is developed by English Mathematics professor name Charles Babbage.
Charles Babbage is also known as the father of Computer.
He designed the analytical engine that was designed on the basic framework of the computer as we are using it nowadays.
Generally, a computer can be classified into three generations, each generation has the gap of certain time period.
Each generation gives some improvement on existing generation
