There are three basic operations in digital electronics, i.e. OR, AND and NOT operation. At first I would like to discuss about AND operation.

When all the input conditions are true then the output will be true. If one or more input conditions are false, output will be false. In simple words AND operation is an operation where we check whether all inputs are true.

Boolean expression for AND operation:

It is read as x equals A and B.

So if we apply this on digital electronics, x will be high or 1 if A and B both are high. Truth table of a two input AND gate is given below. From the truth table we see x is 1 only when A and B both are 1.

AND gate may have two, three or more inputs but output is never more than one.

In the Boolean algebra section I have discussed how it is different from ordinary algebra. But from the truth tables above you must have noticed that this is like ordinary multiplication. This can be helpful in evaluating logic operations.

As I mentioned above AND operation is one of three basic operations in digital electronics, perhaps you are wondering how AND gate electronic circuit is designed. I have discussed that in AND gate section.