Therefore, as an example your standard 1000W kettle uses 1000 Joules in a second. (Or 2000 Joules in two seconds or 500 Joules in half a second and so on.)
A Joule is a unit of energy (or 'work done') and is defined, IIRC, as the amount of work done to exert a force of one Newton through a distance of one metre. It can also be defined as the work needed to move an electric charge of one coulomb through through a potential difference of one volt.
The latter equates to a current of one amp going through a resistance of one ohm for one second.
You'll most commonly see Watts in regards to electrical items, but it is used for a massive variety of things, such as heat dissipation.
Chipmunk gave a good answer. I'll add my .02. Are you aware that watts=volts x amps? The standard comparison is a water hose. Amps is the flow rate, volts is the water pressure. Another analogy is horsepower, if you are mechanically inclined. In fact, horsepower and watts are directly convertible. 746 watts=1 hp. Torque is similar to volts, rpm (engine speed) is similar to amps.