Explain the high-level reasons that are responsible for the development of selenium tools from Selenium IDE to Selenium RC?

Selenium IDE is the easiest of all the tools in selenium suite to learn and install (It’s a browser plugin). There was a major problem with Selenium IDE and that is, it could validate only basic flow like U.I fields or a straight application flow. In order to execute complex scenarios where we need to implement conditional logics or looping this wasn’t effective enough as to implement loops and conditions, we need assistance of programming language and selenium IDE was not developed to make use of any programming language in-fact this was the advantage of Selenium IDE that it did not need any programming knowledge. Also, initially, this did not support cross-browser testing, confining its support only for Mozilla and much later for chrome.

This is where selenium RC comes into the picture as it made Selenium executing complex scenarios as well as it needed programming language and supported a wide variety of browsers for test execution.