Can anyone help me in understanding the difference between Selenium RC and WebDriver and which one is better and why?
Selenium uses JavaScript to automate web pages. This lets it interact very tightly with web content, and was one of the first automation tools to support Ajax and other heavily dynamic pages. However, this also means Selenium runs inside the JavaScript sandbox. This means you need to run the Selenium-RC server to get around the same-origin policy, which can sometimes cause issues with browser setup.
WebDriver on the other hand uses native automation from each language. While this means it takes longer to support new browsers/languages, it does offer a much closer ‘feel’ to the browser. If you’re happy with WebDriver, stick with it, it’s the future. There are limitations and bugs right now, but if they’re not stopping you, go for it.
Selenium Benefits over WebDriver
Benefits of WebDriver Compared to Selenium