This is correct for Verizon and their devices. Sprint however doesn't use a SIM card in their phones. Sprint is CDMA/LTE based on all their newest devices since about 1st/2nd quarter of 2012. Prior to this Sprint's network was CDMA/WiMax (4g) but again Sprint still didn't use SIM cards. Sprint does offer both voice/data over 4G/LTE connections on most of their phones supporting this feature now.
LTE in a nutshell without all the fancy talk is high speed internet for mobile devices. Common CDMA/GSM band based phones (3g service) are limited and normally average at best around 1-1.5 mbps download speeds. LTE however allows much much faster network speed and bandwidth to the customers on the network, speeds can reach well into the 30-40+ mbps range on a good day in a strong reception area. Normally most LTE speeds average I'd say at least 5-15 mbps download rates on any network offering LTE (4g). As I said there is a much more complicated and detailed explanation of what LTE and CDMA, etc all mean but for simplicity I covered the basis.
Hope this helps.
Telling a member looking for help to "search" or "Google" isn't always the best option
We all need to help each other out, that's what a community based forum is all about