Selenium internals [closed]
First there's a layer of javascript code that is used to automate the browser and simulate events, run and verify tests. Next, you run a proxy server - which you point your browser to - that injects this javascript code. Then, you can talk to this proxy server through another port using a set of commands which causes the proxy server to inject javascript code to be run on(or remote controlling) the running browser. Using this framework you can write automated test scripts in a style very much like writing macros for the browser.
Basically it works on following principal . It first Searches for element which you specify in your Locator by searching it in HTML document shown in driver launched browser . After finding element it gets location of Object.After getting that location ROBOT Class methods like MOUSECLICK MOUSE Move etc to perform actions on these locations.I hope this works :-)