Keyword-driven testing involves the use of predefined keywords associated with the actions to be performed, making the test scripts more readable and easier to maintain. On the other hand, data-driven testing primarily revolves around executing the same test script with multiple sets of input data, typically sourced from external files or databases.

"Contextual Testing" is a method where the design or product is tested within the actual environment and context in which it will be used. Unlike lab testing, it ensures the product works in real-world scenarios, capturing the nuances and variables of the actual usage environment.

In the CI/CD ecosystem, an Integration server plays a pivotal role. It automates various phases such as code compilation, testing, and sometimes deployment. This ensures that code changes integrate smoothly with the existing codebase and can be deployed seamlessly.

Jenkins is a widely-used open-source tool designed to support Continuous Integration and Continuous Deployment (CI/CD). It helps in automating parts of the software delivery process, allowing for frequent integration and ensuring rapid and reliable software releases. Jenkins provides a vast plugin ecosystem and integrates seamlessly with many tools in the software development lifecycle, enhancing its capabilities.

While traditional scripted testing is characterized by predefined test cases and steps which are created before test execution, exploratory testing is distinguished by the design and execution of tests in real-time. Testers engage in Exploratory Testing by actively navigating the application and designing tests on the fly based on their observations and insights.

The Page Object Model (POM) is a design pattern that promotes code reusability in automation scripts. In POM, web pages or segments of them are represented as objects within test scripts. When choosing an automation tool, the tool's ability to easily implement POM and reuse code can significantly streamline test development and maintenance.

Unit Testing is the process of verifying individual units or components of a software. Since a sorting algorithm is a singular function or component, unit tests are essential to ensure that it works correctly in isolation. This ensures that the algorithm correctly sorts data under various scenarios before it's integrated with other components.

A/B Testing allows companies to compare two versions of an application (or specific features) to determine which one is more effective in engaging users. By using this method, the company can test new designs or elements to see if they address user feedback about the application being dull or non-engaging.

Integration testing focuses on combining units or components of a software and testing them as a group. It's about validating the interactions between different modules or services in a specified flow to ensure they work together as intended in the system's broader environment. Unit testing, on the other hand, checks individual components, while system testing validates the entire application.

End-to-end testing typically fits just before deployment in the Continuous Delivery (CD) pipeline. In the CI/CD model, continuous integration deals with the frequent merging of code and running unit tests to ensure code integrity. The CD pipeline, on the other hand, ensures that the integrated code is consistently in a deployable state. End-to-end testing, which tests the flow of an application from start to finish, ensures that the system behaves as expected and identifies system-level issues before actual deployment.