If you are on BES, you performed an Enterprise Activation when you got your phone, or your IT Dept did it for you. You have OTA synching of your calendar, messages, tasks, memos, and address book. You have an IT Policy that controls every aspect of your phone, from what web-sites you can visit to how quickly your password times out. Typically BES users have employer-provided phones and plans and use their phones in a corporate environment.
If you bought your own phone and set up a POP email account, you are on BIS. Only your messages sync OTA. For everything else you connect to Desktop Manager (unless you are using one of the GMail apps). You own and control the phone.
There's much more to it than that. For more info, read the BES v BIS article in BlackBerry 101.
Last edited by JeffH; 09-16-08 at 11:18 PM.
Reason: added BIS synching info
