Not much of a difference really. Mainly just that LE uses their own equipment instead of that of the carrier. This brings up a separate FCC issue: Why is it okay for LE to transmit on the cellular bands for this purpose, when it provably can interfere with emergency communications (such as a 911 call)?
It’s a huge difference. The technical difference is that law enforcement is doing an end-run around the carrier to have phones just give up information. Carriers have zero control over that.