About x86 and x64 (online data collation)

Collated the information on the Internet, categorized under, the big like statement is this:
The IBM/PC compatible machine, also known as Intel's I80x86 instruction architecture, is referred to as x86.
x86 does not refer to the 32-bit environment, but refers to the 80x86 architecture, which currently has 32-bit, 64-bit two types.
I've heard of 8 and 16, but I haven't had a chance to read it.

Traditionally, the x86 architecture is 32-bit, but AMD has extended 64-bit environments, and 64-bit hardware supports 32-bit, called AMD64
Intel, called EM64T,EM64T, is an enhanced version of IA-32 in Nature and AMD64, with Xeon using EM64T for physical memory addressing and 256TB (48bit) of virtual memory addressing up to 1TB (40bit). And good support for the execution of existing 32-bit x86 code, which is no different than AMD64, but also the starting point for Intel's development EM64T-to allow the existing x86 instruction set to execute 64-bit code, and continue to maintain good compatibility with 32-bit code. However, due to various limitations, both EM64T and AMD64 can only achieve a larger memory space than the 32-bit instruction set, and can not really do the pure 64-bit instruction set of 1PB (50bit) and 16EB (64bit) of physical memory and virtual memory addressing (IA-64 can do this) , the key is that EM64T and AMD64 are still essentially based on the 32-bit x86 instruction set, but Intel and AMD are using different techniques to extend the x86 instruction set, enabling 64-bit support.

In most cases, AMD64 is not called AMD64 nor EM64T, but x86_64, which shows him and x86 this 32-bit relationship.
In fact, x86 is not all called X86,linux under the i386 i486 i586 i686. such as Intel's new generation of 586 processors, called Pentium (Pentium).
The following 64 is the description of a branch instruction set for this architecture. x86 is a generic term, not a 32-bit environment.
So, to understand the meaning of x86, that X can be 3,4,5,6 and so on.

Extended information:

x86: Refers to the ordinary Intel-made CPU (when presented x86 this notation, the PC is based on 32-bit Intel CPU)
x64:x86_64 abbreviation (also equivalent to AMD64,EM64T), refers to the x86 based on the addition of 64-bit address extensions
IA32: Represents a pure 32-bit architecture
IA64: Represents a pure 64-bit architecture
Represents a 32-bit compatible 64-bit architecture (AMD is the main manufacturer of this architecture).

About x86 and x64 (online data collation)