Strength and Power - what is the difference?

To many this will come across as almost patronising (obviously that is not my intention) however I am quite often surprised by the ability of many to get each one of the above mixed up with one another and at times considering both one in the same.

Strength

The extent to which muscles can exert force by contracting against resistance (holding or restraining an object or person)

Power

The ability to exert maximum muscular contraction instantly in an explosive burst of movements (strength and speed)

Within each one of the above there are what some people consider laws to training them. This will follow once I have completed energy systems (there is only one energy systems, but the parts of that system) utilised most in a BJJ match (Fitness for BJJ) and how to train those systems effectively.

Please be aware that this is aimed at the hobbysit more then the outright professional (although maybe some at a higher level, or anywhere in between could find it useful).