What coordinate OpenGL used?

I saw some people says, that the opengl use right hand coordinate system, but …
When i use the opengl draw something, +z doesn’t point to me as those man says, opposite, the axis point to me is -z,how can that be?!!

“What coordinate OpenGL used” where? At what part of the rendering pipeline? Are you using shaders or just fixed-function matrix stuff?

Sorry , i just a beginner and i set wrong parameters to glOrtho, that problem makes me take a lot of time to thinking what’s going on…
But finally i figure it out…
It will happen, becuse i set an negative number to near and an positive number to far…
Wish i’ll never make the same mistake and thanks for your help

Sorry , i just a beginner and i set wrong parameters to glOrtho, that problem makes me take a lot of time to thinking what’s going on…
But finally i figure it out…
It will happen, becuse i set an negative number to near and an positive number to far…
Wish i’ll never make the same mistake and thanks for your help