ODBC = open database connectivity (drivers that link databases) , well thats limit of what I know on that I just use it. LOL
You can also use Import/Export, h. Actually, if you have an ODBC connection, that's better - I've found using Import/Export is really only useful if you're working with stuff that's found nowhere except your desktop.
ODBC is a connection which permits connectivity based upon all sorts of parameters (I'm oversimplifying here). The idea is that you can connect to any database on any machine, so long as the info is right. At my last gig, we connected with, man (how the heck did we keep 'em all straight??), something like a dozen different servers/databases. Some in Boston, some in New Hampshire, some in Dallas. Very useful thing, ODBC connections, but if you get one letter wrong, the whole shooting match doesn't work, and it's a pain to figure out where you slipped up.
I only have one server right now, but I am working on multiple databases on my server in mysql and having some problems allowing multiple databases under one domain.
I link into a Oracle Terabyte database of multiple Tables and logical views by simply connecting and developing queries using the Microsoft Query tool in Excel. It is wonderful!
A link can also be made with Access developing a subset database of the whole.