What is Intersection of Sets?

Answer 1

You need two sets to have an intersection. If you have two sets, call them R and S,

then their intersection is the set T that contains all elements of R that also belong to S OR all elements of S and also belong to R...it's the same thing.

Answer 2

The intersection of sets S1, S2, ... Sn is a set that consists of all the elements that are in each one of the sets Si where i = 1, 2, ... n.