++ Operator (C# Reference)
The increment operator (++) increments its operand by 1. The increment operator can appear before or after its operand:
The first form is a prefix increment operation. The result of the operation is the value of the operand after it has been incremented.
The second form is a postfix increment operation. The result of the operation is the value of the operand before it has been incremented.
Numeric and enumeration types have predefined increment operators. User-defined types can overload the ++ operator. Operations on integral types are generally allowed on enumeration.