Master-slave flip flop is a type of sequential logic circuit that can store one bit of binary information. It is commonly used in digital electronics for various applications such as memory elements, counters, and registers. This type of flip flop is also referred to as a pulse-triggered flip flop because it changes its output state in response to a specific pulse.

The master-slave flip flop consists of two D flip flops, namely the master and the slave flip flops. These two flip flops are connected in series, with the output of the master flip flop connected to the input of the slave flip flop.

The operation of the master-slave flip flop can be divided into two phases: the master phase and the slave phase.

Master Phase:
During the master phase, the master flip flop is enabled, and the input signal is allowed to propagate through the circuit. The input signal is applied to the master flip flop, and its state is stored. However, the output of the master flip flop is not directly connected to the output of the circuit.

Slave Phase:
During the slave phase, the master flip flop is disabled, and the slave flip flop is enabled. The stored state of the master flip flop is transferred to the slave flip flop, which then becomes the output of the circuit. This transfer of data occurs when a clock pulse triggers the transition from the master phase to the slave phase.

The clock pulse acts as a trigger for the master-slave flip flop. It synchronizes the operation of the flip flop and ensures that the state transfer occurs at the appropriate time.

In summary, the master-slave flip flop is referred to as a pulse-triggered flip flop because it changes its output state in response to a clock pulse. This type of flip flop is widely used in digital electronics due to its reliable and synchronized operation.