What’s the difference between a theory and a law?

A theory is a hypothesis that someone had but has not proven it.

A law is something that is proved.

Example: Sir Issac Newton had a theory on gravity he sat under a tree and then had a conclusion.

A theory is an in-depth explanation of the observed phenomenon. A law is a statement about an observed phenomenon.

the tricuspid valve is present between right atrium and right ventricle

sorry to break it to ya but no one can answer your question it's just

jk but i am serious about the part that most people cant answer it beacuse you did not mention the section you are talking about. but it would if you added some detail and were a bit more specific.