x86 is a term used to describe a CPU instruction set compatible with the Intel 8086 and its successors, including the Pentium and others made by Intel and other companies. This is the CPU architecture used in most desktop and laptop computers. Many 21st century workstations and servers also use x86 processors. In 1985, the original 16 bit x86 architecture was extended to 32 bits with the introduction of the i386 processor. It was extended again to 64 bits in 2003 with the introduction of the AMD Opteron processor. 