The difference between kW and kWh

My kettle uses 3 kilowatts (kW); my energy bill is in kilowatt-hours (kWh). My car has a 60kWh battery; I charge it at a 22kW charger. What's the relationship between kW and kWh?

A kilowatt is a unit of power that describes how fast energy is flowing at any instant. A helpful analogy is to think of water flowing from a tap.

A kilowatt-hour measures the total of that energy over time. In the water analogy, it's how much water is in the bucket that the tap flows into.

Energy consumption (kWh) = Power (kW) x Time (hours)

When I boil my kettle for 3 minutes:

3 x (3/60) = 0.15 kWh

If I want to know how long it will take to charge my car from 0 to 100%, I can rearrange the equation:

Time (hours) = Energy consumption (kWh) / Power (kW)

60 / 22 = 2.727 hours

(In reality, there's more to the calculation since charging occurs at different rates depending on battery levels).

TL;DR: kW is the rate; kWh is the total.