Which phase of software testing involves end-users testing the product?

Beta testing is a crucial phase in the software testing process where actual end-users test the product in a real-world environment. This phase occurs after alpha testing, which is typically performed by internal teams. The main objective of beta testing is to gather feedback from real users to identify any remaining defects and improve the software's usability and performance.

During beta testing, users get access to the software to explore its features and functionalities, often in a controlled setting or as part of a broader public release. Their experiences and feedback provide valuable insights that developers can use to make final adjustments before the software is officially launched. This feedback might involve issues related to functionality, user interface, and overall user experience.

In contrast, alpha testing primarily involves internal teams focusing on finding bugs and issues before the software is given to external users. Gamma testing and release testing are not standard terms in the software testing lifecycle, making them less relevant in this context. Thus, beta testing is the definitive phase that emphasizes end-user involvement in testing the product.