Work is the application of a force over a distance.It can be defined as transfer of energy. =A force of 20 newtons pushing an object 5 meters in the direction of the force does 100 joules of work.
Energy can be defined as the capacity for doing work.You must have energy to accomplish work - it is like the "currency" for performing work. = To do 100 joules of work, you must expend 100 joules of energy.
Power is the work done in a unit of time.Power is a measure of how quickly work can be done. = If you do 100 joules of work in one second (using 100 joules of energy), the power is 100 watts.