Test-driven development

Different approaches to test-driven development (TDD) exist, and a test can vary from a unit test that is run on demand during development, to a unit test that is run during the build of a project, to a test script that will be run as a part of user acceptance testing (UAT). Similarly, a test can be code or a document describing the steps to be performed by a user in order to verify a requirement. A reason for this is that there are different views as to what TDD is trying to achieve. TDD for some teams is a technique to refine requirements before writing code, while others view TDD as a way of measuring or validating the code that is delivered.

UAT
UAT is a term used for the activity during the SDLC where the product or project is verified to fulfill specified requirements. This is typically performed by members of the business or a selection of customers...