TestNG vs Selenium comparison of testing frameworks
What are the differences between TestNG and Selenium?

	TestNG https://testng.org/doc/documentation-main.html	Selenium https://pypi.org/project/selenium/
Programming language	Java	Python
Category	Unit Testing, Intergration Testing, End-to-End Testing	Web Automation
General info	TestNG is a testing framework for the Java programming language inspired by JUnit and NUnit TestNG is similar to JUnit and NUnit but with newer functionalities such as: annotations, test that your code is multithread safe, flexible test configuration, support for data-driven testing (with @DataProvider), support for parameters, powerful execution model (no more TestSuite) and more... It's also designed to cover all categories of tests unit, functional, end-to-end, intergration... etc	Selenium is an open source tool used to test web applications Selenium is a powerful testing tool which can send standard Python commands to different browsers, despite variations in browser design. It also provides extensions to emulate user interaction with browsers, a distribution server for scaling browser allocation, and the infrastructure for implementations of the W3C WebDriver specification that lets you write interchangeable code for all major web browsers
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	No
Client-side Allows testing code execution on the client, such as a web browser	Yes The scope of testing with testNg is wide and you can test various front-end functionalities and behaviours with it	Yes It is primarily a browser automation tool which tests front-end components and functionality
Server-side Allows testing the bahovior of a server-side code	Yes You can test server-side functionalities and behaviours with TestNg	Yes It can perform Unit tests and can test various components and behaviours in the backend using a BDD or TDD approach
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes Fixtures are inbuilt into testNG, these are the annotations which are: @BeforeSuite, @AfterSuite, @BeforeTest, @AfterTest, @BeforeGroups, @AfterGroups, @BeforeClass, @AfterClass, @BeforeMethod, @AfterMethod	Yes By writing your Selenium WebDriver tests in PyTest, this gives you access to Pytest's powerful fixture model
Group fixtures Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.	Yes You can use various fixtures to setup environments for group tests	Yes One can group fixtures if accessing Pytest's fixture model
Generators Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.	N/A	Yes By using a library such as Faker or Fake-factory
Licence Licence type governing the use and redistribution of the software	Apache License 2.0	Apache License 2.0
Mocks Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)	Yes By Use of an external library like mockit which intergrates well with testNG	Yes It includes support for mocking
Grouping Allows organizing tests in groups	Yes Multiple test cases can be grouped more easily by converting them into testng.xml file, in which you can make priorities which test case should be executed first	Yes By using the TestNG feature with which we can create groups and maintain them easily
Other Other useful information about the testing framework