What is selenium? Selenium is opensource tool used to automate web based applications for testing. It allows testers to do cross browsing testing in web browsers like chrome, Edge and Firefox. Use selenium we can automate the web applications like website opening, login page, filling forms and clicking buttons etc. Selenium also supports many programming languages like python, Java, C# and JavaScript. Selenium WebDriver is commonly used for automation. Selenium consists several tools designed for different aspects of test automation. They are Selenium WebDriver, Selenium IDE and Selenium Grid. Selenium WebDriver is a language interface to browser like ChromeDriver to control the browser to use for automation. This is used to make automation faster and more reliable. Selenium IDE is a browser extension for browsers for Chrome,Firefox and Edge. It is used for record and playback functionality. Selenium Grid is a tool for running test cases on multiple machines allows faster test execution. Why do we use selenium for Automation Testing? Selenium is a free and open source tool which will be accessible to Everyone. It supports multiple languages. It is mainly used for automating repetitive tasks. It automates the Regression Testing, Functional Testing, Cross browser Testing, End to End Testing, Data Driven Testing and UI testing. As we know it supports different browsers. It also helps testers to run the same test cases on different Environments. Selenium is very flexible and used for continuous integration helps to run the automated test scripts to run on daily basis also detects the issues early. Because of this the test results are more accurate. It also integrates with third party tools Jenkins, Test NG , docker and Appium. It automates the real world applications like E-Commerce websites, Banking and Finance and Healthcare Applications What is the relevance of Selenium in Automation Testing using Python? Python is popular programming language easy to read and write. Python with selenium automation will be easy. It requires less code and easy to maintain. It has some useful features for better test reports, to reuse code and for test execution. Selenium with python is very useful in Agile methodology and DevOps. Also python is the primary language used for Artificial Intelligence(AI) will be very useful to do automation testing with AI efficiently to improve Test coverage and release cycles.