The union of two sets A and B is a set C consisting of all the elements that lie either in set A or in set B. For any two sets A and B `AUB = BUA`

The intersection of sets A and B is a set that only has elements present both in set A as well as set B. For any two sets A and B `AnnB = BnnA`

For two sets A and B the elements that lie in A but not in B are represented by the relative complement. This is denoted as A - B or A/B. In the case of the complement function `A - B != B - A`

**Further Reading**