From an ambition to a shared agreement
“Make the checkout step easier” expresses a useful ambition, but different people could interpret it in completely different ways. Requirements turn that ambition into clear needs and constraints. Acceptance criteria make individual pieces of work testable.
For example, a requirement might say that customers can buy without creating an account. Acceptance criteria for the checkout ticket could specify that a guest can enter delivery details, pay, and receive an order confirmation without seeing a password field. The team can check those conditions before release.
Good requirements leave room for solutions
Requirements should usually describe the outcome or capability rather than dictating every implementation detail. That lets designers and developers find the simplest effective solution.
Useful acceptance criteria let the team answer “does this pass?” They cover important exceptions as well as the expected path. A user flow can reveal alternative routes people may take. Requirements for accessibility, privacy, performance, and reliability also matter, even when the main journey seems simple. Record decisions and open questions so the team can revisit them.
While requirements and acceptance criteria describe a work item’s expected behaviour, a team’s definition of done covers the required quality steps that apply to many different work items.