What is Apple–Intel architecture?

The Apple–Intel architecture, or Mactel, is an unofficial name used for Macintosh personal computers developed and manufactured by Apple Inc. that use Intel x86 processors, rather than the PowerPC and Motorola 68000 series processors used in their predecessors or the ARM-based Apple silicon SoCs used in their successors. With the change in architecture, a change in firmware became necessary; Apple selected the Intel-designed Extensible Firmware Interface as its comparable component to the Open Firmware used on its PowerPC architectures, and as the firmware-based replacement for the PC BIOS from Intel. With the change in processor architecture to x86, Macs gained the ability to boot into x86-native operating systems , while Intel VT-x brought near-native virtualization with macOS as the host OS.