A task is a distinct piece of work or action that has to be carried out as part of a project.
In planning, tasks (often called activities) are the smallest units of work shown on a programme. Each task has a duration, resources and links to other tasks, and together they define the sequence of work and the critical path. Breaking a project down into well-defined tasks also helps cost control: if each task has an agreed budget and a measurable output, progress can be valued and compared with cost. A well-defined task should have:
- a clear start and finish
- an identifiable output that can be checked as complete
- an owner responsible for delivering it
- a duration and resources that can be estimated
Related terms: activity, programme, work breakdown structure, critical path.

