What is the difference between sub set and proper sets

In set theory, a subset is a set containing some or all members of another set. For example, if the set S is defined as { a, b, c }, then { a }, { a, c } and { a, b, c } are all s...

A is subset of set B if every element of A is in B . Let B={1,2} then if A is subset of B then A can be phi, {1},{2},{1,2}...that means A set is subset of itself. But a proper subs...