OpenGL® is a widely adopted 2D and 3D graphics API available on many desktop platforms. It features hundreds of extensions to support the latest GPU features.
Vulkan is the new generation, open standard API for high-efficiency access to graphics and compute on modern GPUs, available on desktop and mobile platforms.
OpenGL ES is a 2D and 3D graphics API for embedded devices. It's widely used in the mobile space and available on almost any mobile device.