A test case is a set of instructions or steps to verify the functionality of a system or application. There are various synonyms for the term test case, including "test scenario," "test script," "test plan," and "test suite." Test scenario refers to a specific condition or scenario that a software application must be put through before it can be released. A test script is a set of instructions that define test cases within a test scenario. A test plan is a comprehensive document that outlines all the testing activities and procedures that must be followed during quality assurance processes. Lastly, a test suite refers to a set of test cases that need to be executed together to ensure an application's functionality.