Explain the first to four generations of a computer ?

First generation are

a) they are unreliable

b) they are very costly and

c) huge in size

Second generation are

a) they use a transistor

b) smaller in size compared to first generation

c) they are faster than the first generation

Third generation are

a) its more reliable than the first generation and the second generation

b) faster than first generation and the second generation

c) consume less electricity

Fourth generation are

a) they are very cheap

b) they are very small in size

c) they are portable and reliable

Explanation:

explanation is in the answer