[wolfgke]

> Below UEFI is the BIOS, or the firmware formerly known as the BIOS.

Source?

As far as I am aware, UEFI is a replacement for BIOS.

[Rusky]

I believe they're using BIOS in a more general sense. You're right that UEFI replaces the old BIOS APIs that bootloaders used, but there's still firmware (e.g. coreboot) below or part of its newer APIs.