In it's simplest form, the XOR operation describes the binary operation that outputs TRUE when both inputs differ. Although it is not limited to binary or even having two inputs, it is most commonly used in its binary form for file manipulation. The simplest example would be the following:

You're given a byte. The byte goes as follows:

0010 1010

You're given a second byte. This one looks like:

1100 0010

Performing the AND operation on this would yield:

0000 0010

Performing the OR (Not XOR) operation on this would yield:

1110 1010

Finally, performing the XOR operation would yield the following:

1110 1000

One more, for quick practice. The following two sentences:

Like the instar, tunneling to the surface

and

Like the cicada, burrowing to the crust

would yield (as a binary number, punctuation excluded):

0000 000 111111, 101101000 00 000 1111111