https://software.intel.com/en-us/articles/ia-32-intelr-64-ia-64-architecture-mean/
Intel® compilers and libraries support three platforms: general combinations of processor architecture and operating system type. This section explains the terms that Intel uses to describe the platforms in its documentation, installation procedures and support site.
IA-32 Architecture refers to systems based on 32-bit processors generally compatible with the Intel Pentium® II processor, (for example, Intel® Pentium® 4 processor or Intel® Xeon® processor), or processors from other manufacturers supporting the same instruction set, running a 32-bit operating system.
Intel® 64 Architecture refers to systems based on IA-32 architecture processors which have 64-bit architectural extensions, for example, Intel® CoreTM2 processor family), running a 64-bit operating system such as Microsoft Windows XP* Professional x64 Edition or Microsoft Windows Vista* x64. If the system is running a 32-bit version of the Windows operating system, then IA-32 architecture applies instead. Systems based on AMD* processors running a 64-bit version of Windows are also supported by Intel compilers for Intel® 64 architecture applications.
IA-64 Architecture refers to systems based on the Intel® Itanium® processor running a 64-bit operating system.