Definition
Clear criteria for determining the real "finished" of the task in the agile development.
In detail
Definition of Done (DoD) is a clear checklist of criteria in agile development used to determine whether a work item is truly "done." It addresses the issue of inconsistent understanding of "done" among team members, avoiding ambiguous states such as "code written but not tested" or "feature developed but not integrated." Unlike user story acceptance criteria, DoD is a unified requirement for all work items, typically including coding, testing, documentation, integration, etc. Its output is a team-consensus completion checklist ensuring delivery quality.
Example in practice
At the Sprint planning meeting, the team collectively defines the DoD, for example, "code reviewed, unit tests passed, integration tests passed, documentation updated." When a developer claims a user story is complete, they must check against the DoD item by item; only when all are satisfied is it considered done. This avoids ambiguity in "done," improves deliverable quality, and reduces rework.