Define render border ???

Support Basics & Interface
1

Hi, I would like to know how does work the hotkey “Shift-B”?
I read that it was for defining a render border or zone, but
in the camera view or the 3d view, when I use it, I got a cursor for defining a zone but nothing else, the render still work for all the view :x

2

Turn on “Border” in the DisplayButtons (F10), and maybe also “Crop”.

3

Thanks a lot! It work perfectly now!!
(sometimes I’m a little slow on understanding :o )