Whats the point of a double?

Question

I don't really understand why anyone would need a double, what the difference between an 8 bit number vs a 4 bit number?

Answer 1

16 as an unsigned binary number is 10000, which is 5 bits.
Also, double can store floating point numbers (for fractional values) but int stores whole numbers

Answer 2

Because some numbers need 5 or more bits to be represented

Answer 3

Dan Walker Example?