Sites vs Site Collections

Now this is a question i do not fail to ask anyone who appears for a sharepoint interview... 

Now, Mr/Miss ____ I am impressed to hear what you have done with sharepoint; Tell me this, a client, say the HR department asks you to create a few sharepoint pages for them.. they have certain specific information to be displayed under HR India, HR China etc., for each country and they also have common content for HR department itself - Will you create a HR Site and subsites or will you create a HR Sitecollection? How would you justify it and what is the real difference between the two?

 

I would accept both the answers, but i generally look for is the reasoning the candidate gives for either of the solution

 

Here is what i would love to hear:

Every webapplication has one content db of its own and the wss deployment has a common configuration db to store all config information of all web apps in the farm.. (why do we need this information here? :) just because i do not want to create a new post just to write this small but very important information )

 

Now back to sites.. consider a site as a big box.. which can have contents like list, doc libs etc. and also content displayers called pages.. it is like this - if you open the box, you will see different pages which can show a different perspective of what the box contains. 

Now these boxes can contain other boxes inside them which can have contents, pages and more boxes inside them and so on. Each of this box inside another box is called a subsite..

What more, we can lock these boxes and the data within the boxes and provide keys to specific individuals to access the contents and pages.. this is authorization

Additionally, we can color the boxes and the display the pages, paste stickers brand them as and how we want.. this is called setting a theme..

 

All this is great,, but where do these boxes reside.. as i told they can reside in another box.. but where does the top most box reside --> inside a logical entity called site collection.. though it is called a site colleciton it has only one top level site which can have any number of site under it and further down (ie why  it is a collection)

 

Now would you give your HR department a site or a site colleciton.. 

By creating a site collection, i can just assign my HR Director and recruitment manager as site collection administrator and wash my hands off with respect to handling the administrative burden to my HR director (do you think they can pull it off.. :) )

I can of course create site collection specific groups and assign certain permissions which they can use to authorize their sites and contents

I can also create some content types and columns that they can use in their lists and which is common for all items

Further, i can set up backup, restore copy etc., for their site collection specifically !! 

Once we have an idea of these concepts we can pick an option based mainly on how independently the content needs to be managed.

pick your pick..