Buttons for Logged-In and Logged Out Users

Hello,

I’ve got 3 Buttons in my Header: Register , Login and Profile.

Is there a special super secret WordPress Php Tag to show the Register and Login – Button only to/for Guests and the Profile button only to/for Logged in Users.

so something like: if a guest then <blabla guest>log in</blabla guest> if not then <blabla member>log in</blabla member>.

I’m not a very good coder but somebody told me something with “if else” … well It’s all Greek to me ??