∪
Symbol  Format  Data 

∪  Code Point 
U+222A 
TeX 
\cup 

SVG 
The set union symbol (∪) is used in math to represent the union operator in set theory. Typically, the symbol is used in an expression like this:
In plain language, this means the union of the set A with the set B.
The cap symbol is used in mathematics as the set intersection operator. It also is used in probability to represent the occurrence of two events.
The set union operation is denoted using the cup symbol. The union of two sets returns the combined elements of both sets. Duplicates are ignored.