kWh is the written short form of kilowatt-hour (or kilowatt hours) — the unit that measures how much electrical energy you have used, not how strong the supply is at one moment. A kilowatt (kW) is a rate, like speed; a kilowatt-hour is an amount, like distance.

kWh is the written short form of kilowatt-hour (or kilowatt hours)kWh是kilowatt-hour（或kilowatt hours，千瓦時）的書寫縮寫，the unit that measures how much electrical energy you have used是用來量你用了多少電能的單位，not how strong the supply is at one moment不是量某一刻電力供應有多強。A kilowatt (kW)千瓦（kW）is a rate, like speed是一種速率，就像速度；a kilowatt-hour千瓦時 is an amount, like distance是一種總量，就像距離。

If something uses one kilowatt and you leave it on for one hour, that is 1 kWh. That is what an electricity bill is counting.

If something uses one kilowatt如果一個東西用一千瓦的功率，and you leave it on for one hour開著用一個小時，that is 1 kWh那就是1 kWh。That is what an electricity bill is counting電費單算的就是這個。

You will see it written kWh, sometimes kW·h or kW-hr. The W is a capital because it comes from the name Watt.

You will see it written kWh你會看到它寫成kWh，sometimes kW·h or kW-hr有時候也寫成kW·h或kW-hr。The W is a capitalW要大寫，because it comes from the name Watt因為它來自瓦特（Watt）這個名字。

Though actually, people mix up kW and kWh all the time, even on boxes in the shop: one is how hard the machine works right now, the other is how much energy you have already spent.

Though actually不過，其實 people mix up kW and kWh all the time大家常常把kW跟kWh搞混，even on boxes in the shop連店裡商品的包裝盒上也一樣：one is how hard the machine works right now一個是機器現在做工做得多用力，the other is how much energy you have already spent另一個是你已經花掉了多少電能。