Type Distinctive shape Rectangular shape Boolean algebra between A & B Truth table
AND AND symbol AND symbol
INPUT OUTPUT
A B A AND B
0 0 0
0 1 0
1 0 0
1 1 1
OR OR symbol OR symbol
INPUT OUTPUT
A B A OR B
0 0 0
0 1 1
1 0 1
1 1 1
NOT NOT symbol NOT symbol
INPUT OUTPUT
A NOT A
0 1
1 0
In electronics a NOT gate is more commonly called an inverter. The circle on the symbol is called a bubble, and is generally used in circuit diagrams to indicate an inverted (active-low) input or output.[1]
NAND NAND symbol NAND symbol
INPUT OUTPUT
A B A NAND B
0 0 1
0 1 1
1 0 1
1 1 0
NOR NOR symbol NOR symbol
INPUT OUTPUT
A B A NOR B
0 0 1
0 1 0
1 0 0
1 1 0
XOR XOR symbol XOR symbol
INPUT OUTPUT
A B A XOR B
0 0 0
0 1 1
1 0 1
1 1 0
XNOR XNOR symbol XNOR symbol
INPUT OUTPUT
A B A XNOR B
0 0 1
0 1 0
1 0 0
1 1 1

In practice, the cheapest gate to manufacture is usually the NAND gate. Additionally, Charles Sanders Peirce (1880) showed that NAND gates alone (as well as NOR gates alone) can be used to reproduce the functions of all the other logic gates, but his work on it was unpublished until 1935. The first published proof was by Henry M. Sheffer in 1913.

  1. ^ Winfield Hill and Paul Horowitz (1989). The Art of Electronics. Cambridge University Press. ISBN 0521377099.