This is the fault of NVIDIA, who, instead of using the terms that had been used for decades in computer science before them for things like vector lanes, processor threads, processor cores etc., have invented a new jargon by replacing each old word with a new word, in order to obfuscate how their GPUs really work.

Unfortunately, ATI/AMD has imitated slavishly many things initiated by NVIDIA, so soon after that they have created their own jargon, by replacing every word used by NVIDIA with a different word, also different from the traditional word, enhancing the confusion. The worst is that the NVIDIA jargon and the AMD jargon sometimes reuse traditional terms by giving them different meanings, e.g. an NVIDIA thread is not what a "thread" normally means.

Later standards, like OpenCL, have attempted to make a compromise between the GPU vendor jargons, instead of going back to a more traditional terminology, so they have only increased the number of possible confusions.

So to be able to understand GPUs, you must create a dictionary with word equivalences: traditional => NVIDIA => ATI/AMD (e.g. IBM 1964 task = Vyssotsky 1966 thread => NVIDIA warp => AMD wavefront).

All the names for waves come from different hardware and software vendors adopting names for the same or similar concept.

- Wavefront: AMD, comes from their hardware naming

- Warp: Nvidia, comes from their hardware naming for largely the same concept

Both of these were implementation detail until Microsoft and Khronos enshrined them in the shader programming model independent of the hardware implementation so you get

- Subgroup: Khronos' name for the abstract model that maps to the hardware

- Wave: Microsoft's name for the same

They all describe mostly the same thing so they all get used and you get the naming mess. Doesn't help that you'll have the API spec use wave/subgroup, but the vendor profilers will use warp/wavefront in the names of their hardware counters.