Originally Posted by yusharap
I am noob. if we acces cmw will break quranti?
No, you unvalid the warrenty only if you root the phone.
The CWM or TWRP are just a type of recovery... If you've never installed a custom recovery you will probabily have a stock one (like Samsung's) or maybe you WON'T EVEN HAVE ONE )... of course it depends on the phone's producer and model.
BTW, if you want to install a custom ROM or flash files, you'll have to root the device