ELI5: Explain Like I'm 5

Finite field

A finite field is like a regular number that has rules that make it special. For example, if you add 2 and 3 together in a regular number you would get 5, but in a finite field you would get 1. In a finite field, if you add any two numbers together, the answer will always be one of the numbers in the finite field. The numbers in the finite field always follow a pattern.