power and work

power is the energy per unit time----J/s

work we usually mean work done-------------J

work done = power x time.
or change of energy = power x time.

work is the amount of energy used (done) to do something in a period of time. power is the rate (per sec) of the work done.

For example, a ball is dropped from a table to the floor. The ball has transformed its potential energy into kinetic energy. Let's say the PE on the top of the table is 10J.

When it falls to the middle of its way, it has
PE = 5J
KE = 5J

the total energy is conserved. ie. 10J.
But the change of energy (ie. workdone) is 5J.

Therefore, workdone = 5J = power x time
power = 5J / time

If the ball takes 2 sec to drop to its mid way, then:
power = 5J / 2sec
= 2.5 J/sec.

power is the rate energy used (per sec),work is amount of energy changed
work---J
power---W or J/s