I'd suggest a slight rewording here because the difference between "integrated" and "discrete" isn't always clear cut:

This extension allows host code to check whether a SYCL GPU device is "integrated" or "discrete". An integrated GPU device often shares memory with the host CPU, while a discrete GPU is often a separate card with its own memory. However, some GPU devices may not fit neatly into either category, so implementors may provide their own judgement when categorizing a GPU device as "integrated" vs. "discrete".

@bashbaug does this seem like a reasonable description? Any suggestions?