Full Definition of a "Hybrid Phone"?

When I was in Alltel on Saturday (8/15) the technician said something about the Delve being a Hybrid phone and that was one of the reasons that the battery life is short.  Could someone please explain to me more about this? Oh yeah, in case you're wondering what i'm doing (even though you all didn't ask!) , im currently sitting at the table typing this topic question, charging my Delve via Laptop and watching my  bars go up and down and then saying "Leaving Service Area" and "Entering Service Area". LOL!