Which stage in the software development lifecycle involves testing and validating the software?

The stage in the software development lifecycle that involves testing and validating the software is the Testing phase. This phase is crucial because it ensures that the software meets the specified requirements and functions correctly. During testing, various types of tests—such as unit testing, integration testing, system testing, and user acceptance testing—are conducted to identify defects and verify that the software performs as intended.

The Testing phase is dedicated to evaluating the quality of the software product. It is in this phase that developers and testers work to uncover any issues or bugs that need to be addressed before the software can be considered ready for deployment. The goal is to ensure that the end product is reliable and meets user expectations.

In contrast, the Planning stage focuses on defining project goals, scope, and requirements, rather than testing the software. The Development stage is where the actual coding takes place, and the software is built based on the design and requirements outlined in earlier phases. The Deployment phase involves releasing the finished software to users, which comes after testing is completed to ensure the product is ready for use.