Polite is having good manners such as opening a door for somebody. You could say that a person is polite. Respectful is a bit different because while somebody can be called respectful it is usually related to something specific. For example, if you were a child and went to an important meeting with adults and didn't interupt them and sat quietly, your behaviour could be called respectful. It can also be used in other contexts like if you were borrowing something from another person and tried to take care of it and not damage it, you are being respectful of their property. Polite is more general and you don't treat something politely. I hope that helps! It's a good question and I can see where it would be confusing. I struggle with words that are similar in my French studies sometimes : p