In Office Space the main character seems like some kind of analyst, maybe a project manager who makes sure things are getting done as planned and addresses. The other two guys from the office were software developers if I remember correctly. The annoyimg lady answering phones was a receptionist.

So it varies widely depending on what needs to be done and who it is assigned to. I have worked in the same IT department for over 15 years and had four different positions working with the same large software systems doing very different work (help desk, testing, requirements, project management). I interact with security people, administrative assistants, and even directors as part of the work.

‘Office work’ is more of a description of the location and setting than the work itself.