Thermal equilibrium

It is observed that a higher temperature object which is in contact with a lower temperature object will transfer heat to the lower temperature object. The objects will approach the same temperature, and in the absence of loss to other objects, they will then maintain a constant temperature. They are then said to be in thermal equilibrium. http://hyperphysics.phy-astr.gsu.edu/

A system in dynamic equilibrium is a system that stays constant throughout.Whenever there is an output,there will also be a input,the rate of the inputs and outputs is the same.That explains why the composition of the system is unchanging in time.
For example, a lake is in a steady state if the water flows in at the same rate as the water flows out. The term dynamic equilibrium used for systems involving reversible reactions. It is said that the rate of the forward reaction is equal to the rate of the backward reaction. http://en.wikipedia.org/wiki/Dynamic_equilibrium