Test Plan: A document outlining the testing strategy, objectives, schedule, estimation, and deliverables.
Test Case: A set of conditions and variables under which a tester determines whether a system or software application is working correctly.
Test Script: A set of instructions executed during the test.
Agile and DevOps Testing:

Agile Testing: Involves continuous testing and validation of software in an iterative and incremental manner.
DevOps Testing: Integrates testing into the continuous integration and continuous delivery (CI/CD) pipeline, emphasizing automation and collaboration between development and operations teams.
Effective software testing helps ensure that the final product is of high quality, meets user expectations, and is free of critical bugs or issues. It plays a crucial role in maintaining user satisfaction and trust in the software product.