The acronym itself doesn't really matter (Standard Portable Intermediate Representation), but the article points out what it is: an intermediate representation.

The acronym itself doesn't really matter (Standard Portable Intermediate Representation), but the article points out what it is: an intermediate representation. It even spells out how it works: Shader API -> IR API [this is where SPIR-V lives] -> IR Vendor It really doesn't matter, since you never interact with it directly (as in it's not a shading language).