x86 architecture and instruction set

For the purpose of this discussion, the term x86 refers to the 16-bit and 32-bit instruction set architecture of the series of processors that began with the Intel 8086, introduced in 1978. The 8088, released in 1979, is functionally very similar to the 8086, except it has an 8-bit data bus instead of the 16-bit bus of the 8086. The 8088 was the central processor in the original IBM PC.

Subsequent generations of this processor series were named 80186, 80286, 80386, and 80486, leading to the term "x86" as shorthand for the family. Subsequent generations dropped the numeric naming convention and were given the names Pentium, Core, i Series, Celeron, and Xeon.

Advanced Micro Devices (AMD), a semiconductor manufacturing company that competes with Intel, has been producing x86-compatible processors since 1982. Some recent AMD x86 processor generations have been named Ryzen, Opteron, Athlon, Turion, Phenom, and Sempron.

For the most...