Selenium is an open-source framework specifically designed for web application automation testing. It supports various browsers and languages like Java, C#, and Python. While other tools like Appium, TestNG, and Cucumber have their specialties, Selenium stands out for web automation.

In environments with tight deadlines and frequent releases, exhaustive testing isn't always feasible. Risk-based testing allows the team to prioritize critical areas and ensures that the most impactful and risk-prone features are tested first. This approach ensures better utilization of limited time and resources.

Load Testing is specifically aimed at understanding how a system behaves under specific loads or demands. It is used to ensure that the application behaves as expected and can sustain the expected user load, identifying bottlenecks or performance issues in the process.

Automated testing offers several advantages over manual testing, but its primary benefit is the reusability of test scripts. Once created, automated tests can be run multiple times across different versions of the software, ensuring consistency and saving time, especially for regression testing scenarios.

Conversion Testing is focused on optimizing user actions to achieve specific goals, like making a purchase or signing up. In the context of an e-commerce site, a drop in sales and registrations post-redesign indicates a possible issue in the user's journey or experience, which Conversion Testing can help identify and rectify.

"Triage" is the phase in the bug life cycle where bugs are prioritized based on factors like their severity, impact, and the resources available. During this phase, the team decides the urgency and the order in which the bugs should be addressed. Verification is the process of checking if the bug has been fixed, while Reproduction is reproducing the reported bug.

UI elements can change their position, style, or other properties frequently. Using dynamic XPath locators allows test scripts to identify elements based on their unique relationships and properties rather than fixed coordinates or attributes that might change. This method ensures greater adaptability and reduces the chance of script failures due to minor UI adjustments.

"Unit Testing" focuses on the smallest unit of the software design (like functions, methods, or classes). Each unit is tested in isolation to discover any discrepancies between its expected and actual outcomes.

The "think-aloud" method is used in Usability Testing. Participants are asked to speak their thoughts aloud while they perform tasks, providing insights into their cognitive processes, decision-making, and how they navigate and interact with the interface, highlighting potential usability issues.

Defect Detection Percentage (DDP) is a vital metric that calculates the ratio of the number of defects detected to the total number tested. It provides insight into the efficiency of the testing process, giving an understanding of how well the testing phase is identifying issues.