Originally Posted by tomthetrojan09
Perhaps someone could explain what a BIS and BES is? The differences?
A lot of someones took the time already.... BlackBerry FAQ - BlackBerryFAQ
Specifically, to address your question, I've copied/pasted from the FAQ;
BIS stands for Blackberry Internet Service. Basically, this is a service from your provider that lets you receive email and access the internet on personal Blackberries. BIS differs from BES, or Blackberry Enterprise Server, in that BIS retrieves personal email whereas BES retrieves corporate email. Normally, BIS provides push email for up to 10 non-corporate email accounts and some form of internet data service, whether that be a set MB limit, or unlimited.