Unlike BIOS, which simply executes code in a disk's first sector, UEFI understands filesystems (primarily FAT32) and searches for specific files: UEFI boot explained (for Linux users)
: Many UEFI implementations offer a graphical interface with mouse support and advanced diagnostics, a major step up from the text-only BIOS menus. How the UEFI Boot Process Works UEFI Boot
: UEFI can initialize hardware in parallel rather than sequentially, and it directly interacts with the OS, reducing the time from power-on to the login screen. Unlike BIOS, which simply executes code in a