Clock is a repeating signal that switches between low and high levels and controls the timing of inputs like a standard clock controls schedules. A trigger is a control signal used to initiate an action and can be either level-triggered or edge-triggered. The basic SR flip flop circuit can be made using two NAND gates or two NOR gates and has two inputs, set and reset, and two outputs, Q and its complement Q'. An RS flip flop adds a clock pulse input to the basic SR flip flop to enable state changes only when the clock pulse is high.

1. WHAT IS CLOCK?
 Clock is nothing but a signal that goes low to high that
again low and repeat..
 It is called clock because it decides the time of input like a
common clock decides our routine.
low
high
falling edge
leading edge

2.  Trigger is a control signal use to initiate an action.
 Trigger device is used to control another electronic
circuit.
 Two types
 Level triggering
 Edge triggering
Positive edge triggering
Negative edge triggering

3. The most basic flip is SR
flip flop.
This basic Flip flop circuit
can be constructed using
two NAND gate latch or two
NOR gate latch.

4.  The SR Flip Flop has two inputs set(s) and Reset(R).
 The SR Flip Flop has two outputs Q and Q .
 The Q output is considered the normal output and is
the one most used.
 Q is just the complement of Q.

7.  The operation of the basic flip-flop can be modified
by providing an additional control input that
determines when the state of the circuit is to be
changed.
 An RS flip flop with a clock pulse(CP) is shown.
 It consists of basic flip flop circuit and two additional
NAND gates.
 CP acts as an enable signal input.