Okay kiddo, so there's this guy named William Shakespeare who wrote a lot of plays a really long time ago. Some of his plays were funny and some were sad, and some were a little bit of both.
Now, some people call some of Shakespeare's plays "problem plays". This doesn't mean there's anything wrong with them, it just means they deal with some complicated stuff. The characters in these plays go through some tough times, and they don't always make the right choices.
For example, there's a play called "Measure for Measure". In this play, there's a guy named Angelo who is put in charge of a city while the Duke is away. Angelo tries to make everyone follow the law very strictly, but then he falls in love with a woman named Isabella. Angelo tells Isabella that he'll let her brother go free if she sleeps with him, but she doesn't want to do that. So then there's all these complicated conversations and tricky situations that happen.
So basically, Shakespeare's "problem plays" are stories that deal with some tough situations and choices. They can make us think about what we would do in similar situations, and they can teach us about the consequences of our actions.