## Foundations of Mathematics## Set Theory |

## What is a subset and proper subset in set theory? |

Simply put, a *subset* is a portion of a set. If set *B* is a subset of set A, then all elements of set *B* are also elements in set A. If *A* and *B* are equal, then both sets are subsets of themselves; the empty set is also considered a subset of every other set. A *proper subset* is a subset other than the set itself.