What is the difference between prefix and postfix increment operations in programming languages?

Prefix increment (++i) increases the value of the variable by 1 and returns the incremented value. Postfix increment (i++) first returns the current value of the variable, then increases it by 1.

Example:

int i = 5;
int a = ++i; // i becomes 6, a = 6
int b = i++; // b = 6, i becomes 7

This is important to consider when used in expressions where the result of the increment is used immediately.