Jim Halpert (John Krasinski) is a paper salesman at the Scranton branch of Dunder Mifflin. He is a good guy, and very intelligent albeit unmotivated. Throughout the four seasons of the show and counting, Jim spends most of his time pining for Pam Beesly and/or engineering pranks at the expense of office-mate Dwight Schrute.
Michael: You know what eats a large amount of the day? Naps. You go to sleep it's light out, you wake up it's dark. That's the whole day. Where did that day go? I have no idea.
Jim: You mean on a weekend.
Michael: [pause] Yes.
Michael: Dwight, what's your middle name?
Michael: Something with a 'K'.
Jim: It's Kurt. Wow, I'm so sad I know that.