Q and Qanon are both names for the same entity. In imageboard culture* it's common to append -anon, -fag, or a Japanese honorific to the name a user gives (or to give them a name containing one of those suffixes.)

*: I would say 4chan isn't a good example of imageboard culture after the eternal September that followed Project Chanology, but apparently they kept that aspect of their culture.

And also Qanon as a movement exist largely outside of the boards at this point. You should see the type of content on Twitter and Youtube for example. I think most Qanon people have never been to the boards ever.