Task

Project management involves a number of responsibilities within a structured environment. Often, to improve efficiency and to minimize expenditure the project management team leader or analyst who is leading the project will delegate various tasks to an individual or a group of individuals on his or her team.
The tasks assigned to the team or its individuals will sometimes change based on three things:
1) The project goal – How will the project result be applied? How will the task help to achieve this result? Does the team understand the goal of the project? Would this task be more beneficial to the goal if performed at a later date?
2) The field – What sort of industry is the project aimed at? Do the workers on the team have experience in this field? Are they suited to the task at hand?
3) The technology – What resources, hardware, or software, are available to complete the project? Are the resources available to complete the task?
As the project progresses the project management team leader may reevaluate, reorganize, and/or change any of the assigned tasks to suit the changing needs of the client or project.

This term is defined in the 3rd edition of the PMBOK but not in the 4th.