What is the primary difference between the test plan, the test design specification, and the test procedure specification?

The ISTQB stands for the International Software Testing Qualification Board, a software testing qualification certification that is recognized at the international level. The test plan, test design specifications, and test procedure specifications are all terms used in software testing.

The test plan describes one or more levels of testing with an outline, the test design specification identifies the associated high-level test cases, and a test procedure specification is a document that describes the step-by-step procedures for executing a test. Documenting all three stages is important dto ensure all team members are aligned and that the process is transparent.