Back To Basics

I am so mixed-up now that its hard to even figure out what i need to know, so let me tell you a story.....

It started about a week ago, when i first started on the server configuration module of my CIW course. I began to get confused concerning the topic of permissions and access levels in IIS 5. Because of this confusion i started to backtrack what i actually knew (or rather, what i thought i knew) about networks. I now find myself realizing that i am not even sure about the basic
types of networks. Anyway, thank you for your patience so far, and without further a-do here comes the obligatory questions.

I thought that a peer to peer network was any network without a dedicated server, so the hosts (computers) on the network communicated with each other directly. I also thought that once you added a server to the network, all the shares that were once stored on the individual computers are now moved to the server, and that the individual hosts no longer actually communicate with each other to access files, printers, etc.

However, now I am starting to think that i am wrong about this, and that the hosts may indeed still keep some shares on themselves to be accessed by the other hosts on the network.

It is this method of ACCESS that is confusing me.

QUESTION 1
Do the hosts now have to ask the server to fetch the shares on the other hosts, or can each host still have direct access to any other host?

QUESTION 2
A book i have states "a peer-to-peer network does not regulate user access from a central point". To me, this implies that using a server on the network somehow centralizes access, BUT ACCESS TO WHAT??. Does this mean access to the server that has just been installed, or that the server is responsible for giving permission for host "A" to connect to host "B" to access the shares stored on host "B

QUESTION 3
The same book also states (regarding user-level-access and some kind of access list)...."this access list can be central to a particular server or to an entire network"
WHAT THE HELL DOES THAT MEAN???
Does it mean that this list can be either stored on the SERVER (CENTRAL) or EACH HOST("entire network").

I hope one of you guys can figure out,at least, where i am getting confused because the more i read the more i seem to tie myself up