How many in the IDT system and why?

Question

Operating Systems

I read that there are as many IDT systems as there are processors. And why? Why is it not alone or does not each process / thread have its own?
Another question: can a process have multiple LDTs?

Answer 1

there are as many IDTs in an IDT system as there are processors. And why?

Because in hardware, the APIC interrupt controller chips are separate for each processor, and are programmed independently - each processor can have its own independent interrupt processing logic.