Pam Halpert (née Beesly) is Jim's partner in crime around the Scranton office.
Pam Halpert (born Pam Beesly) is an employee at Dunder Mifflin in the American version of The Office. She is good friends with co-worker Jim Halpert. The pranks the two play on Dwight Schrute form one of the cornerstones of the show.
As of the start of the show, Pam has been dating Roy, her high school sweetheart, for eight years, and engaged for three- this has become a running joke at the yearly office awards show (the Dundies) and one of Michael's favorite punchlines. She's shown as very dissatisfied with her lot in life, wishing she was more assertive and could pursue her true passion- art. Pam has repeatedly gone out of her way to do extra work to please others.
One of the running plotlines of the show has been the unresolved romantic tension between Pam and fellow co-worker Jim Halpert. During the show's first two seasons, she comes to realize that she does in fact have romantic feelings for Jim- but nonetheless rejects him in favor of Roy during the Season 2 finale.
Pam gets cold feet and breaks off her long-running engagement to Roy prior to the start of Season 3, while Jim has used Pam's rejection as an excuse to finally leave Scranton and transfer to the Stamford branch, not speaking to Pam in the process. She begins asserting herself more by moving into her own apartment, getting her own car, and taking art classes- the latter of which had been deemed a waste of time by Roy.
When Jim returns- and brings future girlfriend Karen Fillipelli with him- Pam gets back together with Roy very briefly. It's broken off once more after Roy discovers that Jim and Pam kissed the night Jim confessed, and Roy is fired after trying to assault Jim. She has coffee with him one last time at his request, and the two part on good terms- but not before Roy urges Pam to finally take the plunge with Jim.
Pam decides to be more honest and proactive as well, and is supportive of Jim's effort to get a job in New York during the Season 3 finale. However, Jim returns and the two finally decide to go out on a date.
The two are romantically linked throughout Season 4, with Pam being accepted to art school in the Season 4 finale. She is nearly proposed to, but Jim decides not to at the last moment when Andy Bernard steals his thunder by proposing to Angela Martin. The two become engaged during the Season 5 premiere.
Pam finally manages to stop being a receptionist when she takes on the position of saleswoman for Michael Scott's new paper company with Jim's support. Michael manages to get Pam added to Dunder Mifflin's sales team when a buyout by Dunder Mifflin is offered, finally ending her career as a receptionist. During the Season 5 finale, it's heavily implied Pam is pregnant, and confirmed during Season 6.
The two are married in Niagara Falls, and deliver their first child halfway through the season.