Okay kiddo, so an "appeal to pity" is when someone tries to make you feel sorry for them or feel bad for them to try to get you to do something for them. It's kind of like when you really want cookies before dinner and you start whining and crying to your parents, hoping they will feel sorry for you and give you the cookies.
But sometimes people might use an appeal to pity in a sneaky way, to try to get you to do something that maybe you shouldn't. For example, if someone asked to borrow a lot of money from you and they said "I really need it or else I won't be able to pay my rent and I'll be evicted and homeless," even though it seems like they really need it, they could be using an appeal to pity to get you to give them the money even if you can't afford it or it's not the best idea for you to give them the money.
So it's important to be careful and think before you act on an appeal to pity, and not let someone make you do something you don't want to do just because they're making you feel sorry for them.