Vulkan graphics API is the successors to OpenGL and OpenGL ES API, which will support multi-threaded rendering, move some of the complexity to the applications, and simplify graphics drivers, which may not be a bad things since these tend to be closed source, and bugs may be hard to get fixed. Google, which is now a subsidiary of a new company called Alphabet, has recently announced that Vulkan will be implemented in future versions of Android, although OpenGL ES will still be supported, so developers can select their preferred graphics API for their apps, as Vulkan will be more complex for application programmers than OpenGL ES.
Separately, Imagination technologies showcased their Vulkan driver for PowerVR Rogue GPU on the Nexus Player powered by an Intel SoC including a PowerVR G6430 GPU, and compare the Vulkan demo to the same demo using OpenGL ES 3.0 drivers.
The difference between Vulkan and OpenGL ES 3.0 looks amazing, with Vulkan performing much better, but Imagination explains that this demo is an “exaggerated scenario that is intended to highlight and amplify Vulkan’s strengths. It is not intended to show OpenGL ES in a bad light – we are deliberately using OpenGL ES in a way that it was not designed for.” So I’m not sure if we can draw that many conclusions from the demo.
Imagination Technologies blog post explains the implementation and Vulkan advantage in much more details, such as lower CPU usage, and multi-threading support.