There are three as I recall. One describes a tendency of things to go from an ordered state to a disordered state. One describes a tendency for energy to dissipate. The remaining one is that energy can't be created or destroyed. I don't remember the exact wording of these, or the order that they are typically given in.
zeroth law : If two systems are in thermal equilibrium with a third system, they must be in thermal equilibrium with each other. 1st law : energy can neither be created nor be destroyed but can be changed from one form to another. 2nd law : for an isolated system,the change of entropy with time is either positive or zero.entropy never decrease spontaneously 3rd law : the entropy of system reaches a constant value as the temperature reaches absolute zero.