Exculsive OR Logic

The XOR gate (sometimes EOR gate) is a digital logic gate that implements exclusive disjunction  - it behaves according to the truth table above. A true output (1) results if one, and only one, of the inputs to the gate is true (1). If both inputs are false (0) or both are true (1), a false output (0) results. A way to remember XOR is "one or the other but not both."

This function is addition modulo 2. As a result, XOR gates are used to implement binary addition in computers. A half adder consists of an XOR gate and an AND gate.

it is made of two and gate,or gate & and twoNot gates...

XOR gates are basic logic gates, and as such they are recognised in TTL and CMOS ICs. The standard 4000 series CMOS IC is the 4070, which includes four independent two-input XOR gates. The 4070 replaces the less reliable 4030, but keeps the pinout.

If a specifc type of gate is not available, it can be constructed from other available gates. An XOR gate can be trivially constructed from an XNOR gate followed by a NOT gate. If we consider the expression A \cdot \overline{B} + \overline{A} \cdot B, we can construct an XOR gate directly using AND, OR and NOT gates. However, this approach requires five gates of three different kinds.

An XOR gate can be made from four NAND or five NOR gates in the configurations shown below. In fact, both NAND and NOR gates are so-called "universal gates," and any logical function can be constructed from either NAND logic or NOR logic alone.