What is D-Flip Flop?

Well in electronics , every bit of information is either 0 or 1. And that bit is stored in some physical device on your hard drive or RAM so that it can remember how much of task is over or done and what other task needs to be done.

Flip flop is one such device that stores the binary information which is computed till now and then process that info to get the next bit of info . This cycle continues. The function of flip flop is very similar to one of the latch then what's the difference b/w two?

Difference b/w latch and flip-flop

briefly saying , The Flip-flop has clocking mechanism and latch does not. It means that even if flip flop is given a continues strem of data input which changes ocassinoaly , it will only detect this change after a certain periiod of time regularly.

    Simply saying it is like a senario in which input is standing outside the gate.but the flip flop only opens the gate at lets say 1 min , checks who or what input is there and closes.Then it is not concerned about who is there outside or if the input changed multiple times before next clock cycle.At next cycle it will again check who is outside and the gate closes.

D - Flip Flop

The next state stored(or the bit) will simply be what is feed in the input channel.

Truth Table

here if you look at the transition table closely , the next state stored(Q(t+1)) is similar to the input state(D)

The circuit Diagram

The physical implementation of the D flip flop is - 

State Equation

This is Boolean algebraic expression of next state of the system in terms of current state and input 

Q(t+1) = D