In the field of set theory a superset is a set that contains all the elements of another set. It is the opposite of subset.

More formally, set `A` is a superset of set `B` iff all elements contained in `B` are also contained in `A`. This would be written `A` ⊃ `B`.

For example, if `A` = {a,b,c,d} and `B` = {a,c}, then `A` is the superset of `B`.

Interesting things to note about superset:

- Every set is the superset of itself. (
`A` contains everything `A` contains, doesn't it?)
- Every set is the superset of the empty set. This is sometimes called the null set or written ∅ (∅ in HTML).

See also: proper superset, subset, subset (math).