An American option is like a special type of ticket you can buy that lets you buy or sell something at a certain price, but you can use the ticket anytime before it expires. You might want to buy the ticket because you think the thing you want to buy or sell might go up or down in price, and you want to be able to take advantage of that.
For example, let's say you want to buy a toy that's normally $10, but you think it might go up in price soon to $15. You can buy an American option for $1 that lets you buy the toy for $10 anytime before the option expires, even if the toy goes up in price to $15. So if the toy does go up to $15, you can still buy it for $10 and make a profit. But if the toy stays at $10, you don't have to use the option and you only lost $1.
But remember, you have to use the option before it expires. If you don't use it in time, it's like throwing away the ticket and you lose the money you paid for it. So you have to be careful and make sure you use the option at the right time.