The article provides a comprehensive guide to TestNG annotations, a crucial aspect of the TestNG testing framework widely used in Selenium automation. It details how TestNG, developed by Cédric Beust, surpasses JUnit in controlling program execution flow and enhancing test structure through various annotations such as @Test, @BeforeTest, @AfterTest, and others. These annotations allow for parallel testing, data-driven testing, and the generation of customizable HTML reports, making TestNG a powerful tool for structuring test cases. The article also highlights the prerequisites for setting up TestNG, explains the execution sequence of annotations, and describes attributes used with TestNG annotations to define test methods more clearly. Additionally, it touches on advanced features like @DataProvider and @Factory, which facilitate data-driven frameworks and dynamic test creation, respectively, and underscores the importance of using Java version 1.5 or higher to avoid compatibility issues. The content is enriched with code snippets and examples, aiding readers in understanding the practical application of these annotations in enhancing test automation efficiency and readability.