Pseudorandomness

Pseudorandomness is when something looks like random but is actually made up by a computer. For example, a computer can make up a random sequence of numbers like 1, 4, 12, 5, and 7. They don't look like they have any pattern, so they look like they were chosen randomly. But they weren't! They were chosen by the computer in a way that doesn't look like it was chosen by a pattern. Pseudorandomness is used to make things that look like they were chosen randomly but actually weren't.