Okay, so imagine you and your friend want to buy a really cool toy from the toy store. Your friend tells you they will pay for the toy, but after you leave the store with the toy and your friend, they say they never agreed to pay for it. You may be really upset because you thought your friend was going to pay for it.
To avoid this kind of situation, grown-ups made a rule called the "statute of frauds". This rule says that certain agreements, like buying expensive things, need to be written down and signed by both people involved, so there is proof that they agreed to it. This way, if someone tries to say they didn't agree to something later, there is a written record of it to show that they did agree to it.
The statute of frauds helps people make sure they understand and agree to important things, like buying a house, a car, or a big toy, before they do it. That way, everyone knows what they are getting into and there are no surprises later.