A microprocessor family introduced by intel in 1978 with the 8086. It is a 16 bit (later 32 and 64) extension of the 8008, 8080 and 8085 8-bit processors. Contrary to popular belief, the 8008 was not an 8-bit extension of the previous 4-bit 4004, but rather an implementation of the instruction set from the Datapoint 2200, aprogrammable CRT-terminal.
The 8086 was selected by IBM for their PC, and thus gained a stronghold in the PC industry where it practically is the only viable choice for a PC.
8086 / 8088
The 8088 was a 8086 with 8-bit databus.
Atari PC 1
The 80186 was never used in any IBM PC-compatible. It was a slightly enhanced 8086 that integrated a few periferals to keep chip-count down in embedded applications.
It was used in the Swedish school-computer Compis.
The 386 was the first 32-bit implementation of the x86-architecture. It was available in a cost-reduced “SX” version, that had a 16-bit databus and a 24-bit address bus.