|This info was all taken from wikipedia:|
Intel 8086 = The 8086 (also called iAPX86) is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors.
i186 = The Intel 80186 is a microprocessor and microcontroller introduced in 1982. It was based on the Intel 8086 and, like it, had a 16-bit external data bus multiplexed with a 20-bit address bus. It was also available as the Intel 80188, with an 8-bit external data bus.
i286 = The Intel 80286 (also called iAPX 286), introduced on February 1, 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and Intel 8088. It was employed for the IBM PC/AT, introduced in 1984, and then widely used in most PC/AT compatible computers until the early 1990s.
i386 = The Intel 80386, also known as the i386, or just 386, was a 32-bit microprocessor introduced by Intel in 1985.
i486 = The Intel 80486 microprocessor (alias i486 or Intel486) was a higher performance follow up on the Intel 80386. Introduced in 1989, it was the first tightly pipelined x86 design as well as the first x86 chip to use more than a million transistors, due to a large on-chip cache and an integrated floating point unit. It represents a fourth generation of binary compatible CPUs since the original 8086 of 1978.
i586 (aka P5) = The original Pentium microprocessor was introduced on March 22, 1993. Its microarchitecture, deemed P5, was Intel's fifth-generation and first superscalar x86 microarchitecture. As a direct extension of the 80486 architecture, it included dual integer pipelines, a faster FPU, wider data bus, separate code and data caches and features for further reduced address calculation latency.
i686 (aka P6) = The P6 microarchitecture is the sixth generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is sometimes referred to as i686. It was succeeded by the NetBurst microarchitecture in 2000, but eventually revived in the Pentium M line of microprocessors. The successor to the Pentium M variant of the P6 microarchitecture is the Core microarchitecture.
i786 (aka P68) = The NetBurst microarchitecture, called P68 inside Intel, was the successor to the P6 microarchitecture in the x86 family of CPUs made by Intel. The first CPU to use this architecture was the Willamette core of the Pentium 4, released on November 20, 2000 and the first of the Pentium 4 CPUs; all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst. In mid 2001, Intel released the Foster core, which was also based on NetBurst, thus switching the Xeon CPUs to the new architecture as well. Pentium 4-based Celeron CPUs also use the NetBurst architecture.