Energy conservation is any behavior that results in the use of less energy. 

Energy efficiency is replacing inefficient equipment or appliances with a similar device that uses less energy to perform the same function or task with the same degree of performance or service.

For example: turning a light off is energy conservation while replacing a CFL bulb with a more efficient LED is an energy efficiency measure.

Energy tipThe least expensive energy and the most environmental benefit is the energy not used.  When something is not in use turn it off. Start hitting that off switch today!