@ingeborgdot 

The site name can be whatever you feel is appropriate, if you are only running one site per controller then DEFAULT is fine (unless it annoys you)

Sites are for you have more than one location (Site) controlled by a single controller, this is not that common in experience.  Most people just have one controller per 'site'

@Philbert It doesn't necessarily annoy me, I just like names I guess. 

So, when I have an OC200 controller at one site, and an OC200 controller at another site, but want to combine them into one system, because they are going to be for one system, I don't need a name for both? 

I guess I'll learn more as I get more accustomed to the working system as I go along.

@ingeborgdot 

There is basically 2 things at play, the Controller Name.. and then the Site names..

Say you have   123Company with 2 branches.

If you have a controller on both branches, add both controllers to the same Cloud account and you will see both controllers when you log into the cloud portal (London Controller and Paris Controller for example).   The sites can be called anything as they is only 1 site on each controller.

However if both branches share one controller  (lets call its 123CompanyController), it wll be all you see on the Cloud Portal.   Select it then create 2 sites on that controller.. Paris and London.

Hope that helps!

@Philbert Thank you.  That helps.

How does a company share 1 controller, if there are 2 sites?  What do they use for this to happen? Where would they keep the 1 controller?

@ingeborgdot 

A controller can be shared between two sites, provided that a VPN or tunnel is active for the controller to use.  

London for example could host the controller, and provided it has a VPN link both ways to Paris, then the APs on Paris can be adopted by the London controller.    The two sites wouldn't have to be on the same IP range, each will have its own site on the controller.. just so long as traffic is flowing OK to the controller.

To be honest, the only real time you would opt for a central controller is in the Cloud, on perhaps a server you hosted yourself.   More than likely for a few small businesses or a couple schools etc.    In my opinion.. the OC200 is so cheap its not worth setting up a central server, just stick a controller on each site and be done with it.