A jack makes it nicer but no, if you just run like a long extension cord and have one end comes out like an alien, is fine, you pc/laptop won't mind a bit.
I put a hole in my closet to feed a cable through. It looks bad now, but one day(just before I move when I'm old), I'll just patch it. The other side of the wall has a wall plate so it's fine, and the router is right there.