Selenium automates browsers.

That's it! What you do with that power is entirely up to you.
Primarily, it is for automating web applications for testing
purposes, but is certainly not limited to just that. Boring web-based
administration tasks can (and should!) also be automated as well.

Selenium has the support of some of the largest browser vendors who
have taken (or are taking) steps to make Selenium a native part of
their browser. It is also the core technology in countless other
browser automation tools, APIs and frameworks.
