Nor

NOR is a logic gate it is like OR gate but it is the opposite in how it works. It works like key to current to the circuit, if the output=1 it is on if output= 0 it is off. OR works by adding 0+1=1 but NOR is different than this.

A	B	AB
0	0	1
0	1	0
1	0	0
1	1	0

References: www.allaboutcircuits.com