Selenium vs TestNG: What are the differences?

1. Testing Framework: Selenium is mainly used for automating web applications testing, while TestNG is a testing framework that integrates seamlessly with Selenium for test case execution, grouping, and parallel testing.
2. Annotations: Selenium does not provide built-in support for annotations like TestNG does, which allows for easier test case organization and execution control.
3. Reporting: TestNG offers comprehensive reporting features such as HTML reports, test case-wise reporting, and graphical representation of test results, which are not readily available in Selenium.
4. Parameterization: TestNG allows for parameterization of test cases through the use of data providers, making it easier to run the same test case with different input values, whereas Selenium requires manual code modifications for parameterization.
5. Dependencies: TestNG provides the ability to define dependencies between test methods, ensuring that one test method runs only after the successful execution of another, a feature not natively supported in Selenium.
6. Data-Driven Testing: TestNG supports data-driven testing, where test cases can be executed with different sets of data retrieved from external sources like Excel files, databases, or CSV files, which Selenium lacks in-built support for.

In Summary, Selenium focuses on web automation testing, while TestNG acts as a testing framework that complements Selenium by providing features like annotations, reporting, parameterization, dependencies, and data-driven testing.