訂單就是你買東西或叫外賣的時候，寫下你要什麼的單子。

An 訂單 is a list you write down when buying something or ordering takeout, showing what you want.

買了東西以後，商店會收到你的訂單，然後把東西寄給你。

After buying something, the store receives your 訂單 and then sends the items to you.