What's the difference between "kennen" and "wissen"?
kennen: To know (a person, place, thing, or work). It's about familiarity. Takes an accusative object.
wissen: To know (a fact, information, how to do something). Takes a subordinate clause (often with dass or a W-word) or a direct object referring to a fact.
Example
Ich kenne diesen Mann. (I know this man - familiar with him.)
Ich weiß, dass er kommt. (I know that he is coming - a fact.)
Ich weiß die Antwort. (I know the answer - a fact.)