Misrepresentation is when someone tells you something that isn't true or shows you something that isn't really what it seems. It's like when someone promises to give you candy if you do something for them, but then they don't give you any candy. That's not fair, right?
It can happen in lots of different situations, like when you're buying something from a store or talking to someone who's trying to convince you to do something. People should always tell the truth and show you things as they really are, because otherwise you might make a decision based on something that isn't real.
If someone misrepresents something to you and you find out later, you might be able to ask for your money back or get help from someone in charge to fix the problem.