Logic Gates

Logic gates are physical device which are used to perform logical function.logic gates perform logical operation. In logic gates we can give one or more input and we have one output . every operation is expressed in "1" or "0".
1 means  "high"
0 means "low"

Their are three basic logic gates:-
1.OR Gate
2.AND Gate
3.NOT Gate

1.OR Gate

In case of OR Gate their are following conditions for the Output:-

1. If one of the input is high the output also HIGH it means it gives "logic 1" at the output.

2.If the both the input are low then the output of OR Gate is low it means it gives "logic 0" at the output.

Boolean Expression in case of the OR Gate is 

Y(Output)= A + B

2.AND Gate

In case of AND Gate their are following conditions  for the Output:-

1.If both of the input are high then the output also be HIGH(Logic 1).

 2.If both the input are low then the output also LOW.(logic 0).

3.If 1 input is high(1), other is low(0) then the output also be LOW.

Boolean  Expression in case of the AND Gate is

Y(Output)= A * B

3.NOT Gate

NOT Gate is said as the "INVERTER". In case of the NOT Gate:-

1. If Input is HIGH(1) then Output is LOW(0).

2.If the input is LOW(0) then  Output is HIGH(1).