A prophet (arabic nabi, نَبِيّ) is a person whom Allah chooses and guides. He is sent to confirm and revive the message of Allah. He continues and teaches an existing revelation, while a Messenger brings scripture/revelation with a new law. Every messenger is a prophet but not every prophet is a messenger. The prophets teached us who Allah is, to worship Allah alone, to know what is halal and haram and how to reach paradise.