Edge trigger is triggered by the edge when the pulse rises or falls, including rising edge trigger and falling edge trigger, and edge trigger is mostly used for phase positioning. It is usually obtained by removing the edge with differential capacitor or shaping the edge with Schmidt frequency divider. Pulse trigger is triggered according to the number of pulses, which is mostly used for counting. And it is mostly realized by flipping high and low levels, such as the gate circuit and digital input of single chip microcomputer.