So how can the Xbox one emulate the Xbox360?
Imagine you are a native English speaker and need to read two different books, one in, say, French [or Spanish, etc] and one in, say, traditional Chinese [or Arabic/etc].
Now, let's say as you read these books, you're essentially translating them as you go into English -- in a broad manner of speaking, you're 'emulating' them.
French is fairly easy to translate. The languages are clearly closely related. It certainly requires work, but it's essentially a straight translation.
Chinese is not. It's different symbols, it's different structure. It is far more complex.
I mean, if you were doing a text translation from English to Chinese, Arabic, etc. you'd even need a different keyboard.
While not a perfect analogy by any means, that's how different architectures can theoretically be. Some may share key similarities that make emulation relatively easy... and others may be effectively alien. How many processes can be done at once may be wildly different, how it's all threaded together... it can be hard to emu some things.
