I tried Googling, but couldn't find the info about what I will ask. I
am new to this field, can someone tell me where I can read more about
the problem I am thinking about, to see if I am actually right.

Basically, as far as I have read, PDC is the computer that wins the
"broadcast" battle to become the PDC. What would stop someone coming
to the network (e.g. private LAN), plugging into it and becoming the
PDC for it? How the workstations know which is the legitimate PDC? Am
I wrong about the "broadcast battle" process of selecting the PDC?
What will happen if there are more computers claiming the PDC role?

I am sure this is a basic question (i.e. I am assuming I am not
reinventing the hot-water here - someone must have asked this question
before), that is why I think the best would be to supply me with a
(better brief) text about this and maybe a quick answer(s).