A,B sets

A B ---> this means that all elements from set A are also elements of set B where B is bigger set ( it has more elements (important) )

A B ---> this means that all elements from set A are also elements of set B where A can be equal to B

example: A = { 1, 2, 3 }

B = { 1, 2, 3 }

then this is true: A B , but this isnt A B

but if B is = { 1, 2, 3, 4 }

A B is true and this is also true A B