How computer calculate random. How we can make random function

Question

For example random(6)=1,2,3,4,5,6

Answer 1

Computers can generate truly random numbers by observing some outside data, like mouse movements or fan noise, which is not predictable, and creating data from it. This is known as entropy. Other times, they generate “pseudorandom” numbers by using an algorithm so the results appear random, even though they aren’t.

Answer 2

In programming language?