UEFI vs BIOS Legacy
by Rémi Robichet
Difference between UEFI/BIOS Legacy. Information needed when i was trying to install PopOS on external HDD, i needed to change my BIOS to UEFI in order to create GPT Partition table.
https://linoxide.com/distros/install-pop-os-20-04/
"You will get an alert concerning the action you are taking and the fact that all data will be erased. For the partition type, select GPT if your BIOS is set to UEFI mode. For Legacy boot, select the 'msdos' option. If you are satisfied with your selection click the 'Apply' button."
https://www.malekal.com/differences-uefi-legacy/
https://www.maketecheasier.com/convert-legacy-bios-uefi-windows10/