Selenium is a powerful browser automation tool widely used in the field of automation testing. It helps developers create automated test scripts for regression testing, cross-browser testing, and more. Selenium WebDriver is its core component, supporting multiple programming languages and driving browsers for complex interactions.

Selenium IDE is a simple record-and-playback tool suitable for quickly creating test scripts. Selenium Grid is used for distributed testing, allowing tests to run on multiple machines with various browser and OS combinations.

The Selenium community is active, offering extensive documentation and resources suitable for users of all levels, from beginners to advanced developers.