opengl allows access to the OpenGL stack and, consequently, OpenGL hardware, which may be needed for certain types of graphical applications and those that use CUDA libraries for computation. See Adding OpenGL/GPU support to a snap for more information on how to use this interface.
ⓘ This is a snap interface. See Interface management and Supported interfaces for further details on how interfaces are used.
There was a suggestion to make it more explicit that this interface is needed if you want to use CUDA in a snap. I’ll try to tie this together with other documents if I can.