Pentium is a discontinued series of x86 architecture-compatible microprocessors produced by Intel. The original Pentium was first released on March 22, 1993. The name "Pentium" is originally derived from the Greek word pente (πεντε), meaning "five", a reference to the prior numeric naming convention of Intel's 80x86 processors (8086–80486), with the Latin ending -ium since the processor would otherwise have been named 80586 using that convention.
The die of a Pentium processor
Pentium Dual Core logo
x86 is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the 8086 microprocessor and its 8088 variant. The 8086 was introduced in 1978 as a fully 16-bit extension of 8-bit Intel's 8080 microprocessor, with memory segmentation as a solution for addressing more memory than can be covered by a plain 16-bit address. The term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486. Colloquially, their names were "186", "286", "386" and "486".
The x86 architectures were based on the Intel 8086 microprocessor chip, initially released in 1978.
Intel Core 2 Duo, an example of an x86-compatible, 64-bit multicore processor
AMD Athlon (early version), a technically different but fully compatible x86 implementation
Am386, released by AMD in 1991