AND, NAND example

An AND gate outputs a signal of 1 only when the signals to IN0 AND IN1 are 1, otherwise it outputs 0.
A NAND gate (or NOT AND ) outputs a signal of 0 only if the signals to IN0 AND IN1 are 1, otherwise it out puts 1.
As you can see from the example a NAND gate is the same as an inverted AND gate.