The subset or equal symbol is used in math to denote that one set is a subset of another set or is equal to another set. Typically, the symbol is used in an expression like this:
In plain language, this means that the set is a subset of the set or is equal to the set .
A subset is denoted by the symbol ⊂ and is used to indicate that one set is a subset of another set, but not equal to it.
A superset is denoted by the superset symbol ⊃ and is used to indicate that one set is a superset of another set, but not equal to it.
The superset or equal symbol ⊇ is used in math to denote that one set is a superset of another set or is equal to another set.