An increment is a step size. Incrementing increases a value by the amount of the increment by one step. The opposite of the increment is the decrement, where a number is decreased by the value of the decrement.
In data packet switching, increments are used to count the data packets arriving at packet switching nodes so that overload control can be triggered to reduce the number of incoming data packets in the event of overload. In computer programs, loop constructs count the loop passes by incrementing the loop counter.