What is Selenium?

                

Selenium is an open source (free) testing framework used to validate web applications across different platforms. You can use multiple programming languages like, Java, C sharp, Python any many more to create Selenium Test Scripts. As testing done with selenium tool so it usually referred to as Selenium Testing.

Selenium is not just a single tool, but it is combination of softwares, each piece catering to different testing needs of an organization. 

Here is list of tools,

1. Selenium IDE(Integrated Development Environment)
2. Selenium RC(Remote Control)
3. Selenium WebDriver
4. Selenium Grid 

At the moment, Selenium RC and WebDriver are merged into a single framework to form Selenium 2. Selenium 1, by the way, refers to Selenium RC.