1. Bit 2: http://www.brokenthorn.com/Resources/OSDev19.html
2. Unfortunately googling "systemization" suggests this word has wrong spelling. "Differential electronic connectivity" was not a term I was able to find anywhere in Chapter 6, "Interrupt and Exception Handling", Intel 64 and IA-32 Architectures Software Developer's Manual, System Programming Guide, Part 1.
The latter suggests to me that the OP's question refers to some non-standard* terminology.
*Or straightforwardly wrong: the OP has not earned the benefit of the doubt yet.
3. It appears to me that the question is incorrectly posed, as the seven main structures described here: