X86 CPU, IA-32; X86-64, amd64; em64t, IA-32e; IA-64 (EPIC) meaning and Difference

X86 CPU, IA-32
IA-32 (Intel Architechure-32, Intel 32-bit architecture)
Now Intel x86 series CPU is the cpu Of The IA-32 architecture.

X86-64, amd64; em64t, IA-32e
It refers to the current 64-bit Processor Technology Based on the X86 architecture.

ADM's X86-64, also known as amd64.

Intel IA-32e, also known as em64t.
Em64t (extended memory 64 technology, extended 64-Bit Memory Technology)
IA-32e (Intel Architectur-32 extension) is an extension of the Intel IA-32 architecture.

IA-64 (EPIC)
IA-64 (Intel Architechure-64, Intel 64-bit architecture)
This 64-bit processor is a new EPIC (Explicit Parallel Instruction Computing) CPU developed by Intel. It can be said that it is a future-oriented 64-bit architecture processor, this technology is currently used on the itanium (anteng) processor (currently the highest-end processor.

Reprinted: http://hi.baidu.com/halleyzhang/blog/item/d37c6ef4fb8235d8f2d385ae.html