so which is better dragon or chrome cuz they both look same !
Both are based off of the Chromium source code.
There are changes between the two, but the ones that I consider most important concern privacy. Google Chrome contains a lot of mechanisms which can track you, in one way or another. Whether that is a concern to you or not is up to you. Comodo Dragon has removed those problems, and added some security enhancements.
If you have any more questions feel free to ask.