hen a computer boots it runs its firmware.
There are different kinds of firmware. Dozens across platforms, but for PC compatibles their are two big flavours:
- Firmware compatible with the IBM PCs (1984, 4.77Mhz) Basic Input Output system
- Firmware from the last decade using EUFI.
EUFI is used in any PC from the last decade. They no longer have a BIOS. Period.
But confusingly enough the EUFI firmware still displays 'Press F12' or 'Press DEL' to enter BIOS. I think they do it because people are used to the setups screen to be called BIOS, but it is technicaly incorrect.
A second confusing part are the compatability SHIMs in some EUFI implementations, which make the UEFI firmware compatible with a BIOS firmware. At that stage it often looks like BIOS, feels like BIOS, acts like BIOS,.... but behind the covers it still is EUFI.
Ok, enough of the introduction, lets answer the specific questions:
1. Is the modern good looking Setup GUI part of EUFI?
It can be either. Early BIOS was text only, but near its end there also were graphical BIOS implementations. Same with UEFI, some of them have pure text, some graphics.
It seems to be more capability related (read: more modern faster computers) which decides if you get a text interface, or a graphical interface.
2. Who is responsible for setup screen? BIOS or EUFI?
The firmware. Which on old PCs is BIOS and on new PCs is EUFI
3. And what is the correct way to call the setup screen?
“Enter bios setup”, enter “UEFI setup”?
I would go for 'enter setup' (and then start EUFI, or coreboot, or BIOS, or ...<