BES - Blackberry Enterprise Server (http://na.blackberry.com/eng/services/server/ http://na.blackberry.com/eng/services/server/) typically for businesses. It re

BES - Blackberry Enterprise Server (http://na.blackberry.com/eng/services/server/ http://na.blackberry.com/eng/services/server/) typically for businesses. It requires you have your own Exchange server or similar and someone to set it up for you as it, and has $$$ monthly subscription charges. Most individual (or very small businesses) would use... BIS - Blackberry Internet Service (http://na.blackberry.com/eng/services/internet/ http://na.blackberry.com/eng/services/internet/) which is also generally available as a cheap (<$10 p.c.m.) bolt-on by your service provider (atleast in the UK) on most pay-as-you-go/contract phones and requires little or no setup effort.