What are acceptance criteria and how do they differ from DoD?

Acceptance Criteria are specific conditions that a Product Backlog Item must satisfy to be accepted by the Product Owner. They are item-specific and define what "done" means for that particular story. Example for "As a user, I want to filter products by category": (1) Products list updates immediately when a filter is selected; (2) Multiple filters can be applied simultaneously; (3) A "No results" message shows when no products match; (4) Filter selections persist on page refresh. Definition of Done (DoD) applies universally to every Product Backlog Item — it's the quality standard that every increment must meet (code reviewed, tests passed, deployed to staging, etc.). The relationship: an item must satisfy BOTH its acceptance criteria AND the DoD to be considered complete. Acceptance criteria answer "did we build the right thing?"; DoD answers "did we build it right?" A PBI can meet acceptance criteria but fail DoD (e.g., works correctly but has no tests written).