Mobile usability testing primarily focuses on assessing the user's experience and interface interactions. It ensures that the app is intuitive, easy to navigate, and meets the expectations of the users. While functionality, load time, and security are vital, usability testing centers on the user's overall experience.

The "Exit Criteria" in test planning defines the specific conditions or metrics that need to be achieved before the software can be released. It ensures that the product has reached a certain quality standard before it's deemed fit for production.

Although Exploratory Testing can be freestyle, many testers use "Test Charters" to guide their exploration. Test Charters help in providing a clear context, scope, and purpose of the exploration while allowing testers to document and manage their findings efficiently.

System testing is conducted on an integrated software to evaluate its complete and end-to-end behavior. It ensures that the entire software functions according to specified requirements. This phase tests the entire software as a single entity.

Change Control in Configuration Management involves a systematic approach to manage changes by evaluating, approving, or disapproving changes, ensuring that changes are documented, and ensuring that configuration items maintain their integrity throughout the lifecycle.

Vulnerability Scanning is a systematic approach that uses specialized tools to identify, rank, and report potential vulnerabilities in a computer system or network. It provides an overview of the security flaws but doesn't necessarily exploit them like penetration testing.

JMeter is a popular open-source tool primarily used for performance testing. It allows testers to simulate multiple users and test how much load an app can handle, ensuring the app performs well under heavy usage. While it started for web applications, it is now used for mobile application load testing as well.

The primary difference between test planning and test strategy is their purpose and scope. While test planning is a document that outlines the specifics of the testing process for a particular project, test strategy provides an overarching approach to testing across multiple projects or for an entire organization.

A Code Review is a systematic examination of the application's source code. It's conducted to find vulnerabilities or bugs before the app is deployed. While tools like Selenium and JUnit focus on functional testing, and Wireshark on network analysis, only a thorough code review provides insights into code vulnerabilities.

Path testing is a white-box testing technique that ensures every path through the program is tested at least once. It is particularly focused on evaluating the program's internal logic paths to ensure all code branches and potential execution paths are tested.