Difference between Selenium 1.0 and Selenium 2.0?

Selenium 1.0 also known as Selenium RC and Selenium 2.0 known as Seleniuim WebDriver.
Differences as below...

Selenium 1.0 (RC)	Selenium 2.0 (WebDriver)
Need to start Remote server before execution.	No need to start any server.
Support some of the browser like.. IE, FireFox, Chrome and Opera. Can not support headless HTMLunit driver	Support all the browser like.. IE, FireFox, Chrome ,Opera, headless HTMLunit, Android
Core engine is Javascript based	Interacts natively with browser application
Very complex architecture	Simple and easy architecture
It calls Selenium Core to execute and control browser	Directly interact with browser
API are more matured but contain redundancy and often confusing	API's are simple and no redundancey.
Built in test result generator and automatically generate HTML file	No Built in result file generator
It ‘injected’ javascript functions into the browser when the browser was loaded and then used its javascript to drive the AUT within the browser	Selenium-WebDriver makes direct calls to the browser using each browser’s native support for automation