What is the difference between a good friend a bad friend a true friend and just a friend and how can you tell which is which?

A good friend is a good friend, a person who laughs with you not at you. A true friend is true to you and is like a sister and doesn't talk behind your back. A bad friend doesn't care for you and doesn't play with you at all even if they live by you. You can tell which is which by watching closely at every move they make and see if their true, just a friend, bad a good friend.