in sharepoint there are a lot of terms that may be confusing to new sharepoint admins, or even to existing ones.
since a lot of the words have other meanings than what sharepoint uses them for, it can be a bit tricky. i know when i was starting out with sharepoint i was very confused for a while because of the ambiguity of the words
so let's take it from the top:
wss / windows sharepoint services - this is a free product from microsoft (comes with windows server). it gives you all the basic functionality of sharepoint including document libraries, lists, even things like email integration.
moss / microsoft office sharepoint server - this is an add-on to wss which gives some very cool additional features. some examples are excel services, infopath forms server, ecm (enterprise content management) and moss enterprise search. this is not free.
also you can't just install moss... moss is built on top of wss, so wss is a prerequisite.
web application / web app - also known as a virtual server (in sharepoint v2) and an web site / application pool (in iis), web apps allow for logical separation of sharepoint content. each web app runs under a different process on the iis web server.
two examples of different web apps are the central administrator site which runs on an arbitrary port number and then standard sharepoint sites which typically run on port 80. they both run under separate processes in iis.
site collection / top level site / parent site / spsite - a site collection is a web site that can contain sub-sites (aka webs), which all share the same owner and administrators of the top level site collection.
a site collection controls global settings that sub-sites underneath it inherit. settings can include permissions, storage quotas, and themes, etc...
webs / sub-sites / spweb - these are web sites that live underneath a site collection. these are almost the same thing as a site collection but the difference is the global settings that are applied from the site collection.
webs can have their own independent settings separate from its parent site collection, but it makes it a bit easier to manage for the owner of the site, that's the idea here.
lists - a list is a generic term used to define the different places to store content in a sharepoint site. some built in lists are document libraries (upload and share word docs), picture libraries (upload pics), and custom lists where you define what you want to store.
ok lets discuss one potential way to set up a sharepoint site.
imagine a organization of 60 people, and then 3 sub-teams of 20 people each.
a potential structure of the team's sharepoint site is a site collection that contains information for all 60 people (ie vacation calendars for the whole team).
then each of the 3 teams could have their own webs, for the smaller teams, which contain all the documents relative to each team.
the url structure could look like:
in this example orgsite is the site collection and team1site, team2site, team3site are the webs.
a picture is worth a thousand words so in my next post i will include some diagrams to better show the relationships.