In a universal set U, the difference between sets A and B is the set of elements of A that do not belong to B.
Symbol
The symbol for the difference of sets is “\” which is read as “less” or “difference.”
Therefore, A \ B is read as “set A less set B” or “A difference B.”
Example
In this universal set U, we have: E \ F = {a, b, f, g}.
As well, U \ F = {a, b, f, g, m, n}