What is the difference between ++m and m++?

If the Increment operator has placed before the operand it Increment first and other operations later. Example:

m=5      

x = ++m;

In this case first Increment the value of m and then transfer the value of m into x.

And

If the Increment operator has placed after the operand it Increment after the other operations. Example:

m=5      

x = m++;

In this case first transfer the value of m and then Increment the value of m.