used when it is not important which person you are referring to, because what you are saying applies to everyone, or everyone of a particular typeAnyone can make a mistake.
If anyone asks for me, tell them I’m busy.
Anyone old enough to remember the war will know how important radio was.
You can invite anyone you like.
anyone else: Sherwood probably knows more than anyone else about the subject.
almost anyone: It was the kind of accident that could happen to almost anyone.