In computing, x86 is the generic name given to the family (architecture) processors based on Intel 8086 by Intel Corporation.
The architecture is called x86 processors because the first of this family were identified only by numbers ending with the string "86": the 8086, the 80186, the 80286, the 80386 and 80486. As you can not have a trademark on numbers, Intel and most of its competitors began to use names that could be registered as trademarks as to the Pentium processor generations later, but the old nomenclature had forged a term for all family.
In other words, we can say that the x86 term refers to a family of the instruction set architecture, based on the Intel 8086. The 8086 was launched in 1978 as an extension of 16-bit Intel was one of eight first who introduced the microprocessor-based segmentation to overcome the 16-bit addressing barrier of the previous chips. The x86 term derived from the fact that the successors to the 8086 also had names ending in "86". Many additions and extensions were added to the x86 instruction set over the years, often with full backward compatibility. The architecture was implemented in processors from Intel, Cyrix, AMD, VIA, and many others.