• Selenium is the framework, helps to test the web application in various browsers like fire fox, chrome,opera.
• It's an open source automated testing tool.
• Its also supports the all the operating systems like windows,Linux, internet explorer,MS edge.
• In selenium test can be coded in many languages like Java, python,perl,PHP and Ruby.
• It's easy to use, primarily developed in Java script.

*Advantages *

1. Time efficiency, when it's comes to manual, each and every test cases we need to check manually, and we need to submit it, it consumes more time and manpower too.
2. Open source availability - biblically can available, multiple browser support.
3. Easy for implementation, reuse ability and integration
4. Flexibility, more efficient with selenium features
5. Reduce the duplicates, minimize the complications
6. Easy to learn and use
7. Parallel test execution, multiple files execution

Selenium for automation

1. Selenium (IDE)
2. Selenium (RC)
3. Selenium WebDriver
4. Selenium Grid

Selenium (IDE)

• Selenium Integrated Development Environment .
• Simplest framework, not required any code.
• it is an easy-to-use interface that records the user interactions to build automated test scripts.
• It was mainly developed to speed up the creation of automation scripts.

Selenium (RC)

• Selenium Remote Control.
• It is supports only the language selenium remote control.
• This is the 1st automated web testing tool, where we can write the code using programming language.
• Here will just write the code using selenium, here only we can able to write the code only, it will not support anything apart from that other functionality like API and SQL.

Selenium WebDriver

• It will be better than other components like Selenium (IDE),Selenium (RC)and Selenium Grid.
• It will support all the web driver actions and automation tool.
• Here we are the client & server, is the one where we are accessing the data.
• Its the 1st cross platform testing framework.
• It served as a programming interface to create and run test cases.

*Selenium Grid *

• It was developed to minimize the execution time of selenium automation testing.
• It allows parallel execution with different browsers & different operating systems.
• It Provide an easy way to run tests on multiple machines