It’s not really software vs hardware, it’s the fixed function pipeline api vs the shader api.

The fixed function pipeline api only does one thing one way with a lot of limitations while the shader pipeline can basically do anything (doesn’t even have to be rendering a 3D scene) as long as it’s fast enough for your purpose.

> It’s not really software vs hardware, it’s the fixed function pipeline api vs the shader api.

...that sounds like software vs hardware though?

Lighting used to run as a fixed (hardware) function and now it runs via a shader (software) function.

It is true, although a specialized form of software that requires extra hardware, GPUs.