IA-32

(Intel Architecture-32) The designation for Intel's x86 family of CPUs. Intel had previously used Intel Architecture (IA) without a number as its x86 technology brand, but changed it to IA-32 when it introduced the Itanium, which was designated IA-64. The "32" is somewhat imprecise because the earliest models of the x86 line were 16-bit CPUs, and later models were 64 bit.

IA-64 vs. Intel 64
Subsequent to the Itanium, Intel added 64-bit models to its x86 line, but could obviously not call them IA-64 chips because IA-32 and IA-64 referred to entirely different architectures. The designation Intel 64 (first called "EM64T") was given to 64-bit models in the IA-32 line. See IA-64, Intel 64, x86 and x64.

IA-32 Microarchitectures

Intel has had numerous microarchitectures within the IA-32 (x86) architecture. These start with the Pentium chip (see microarchitecture).