A:AnswerYou need to have cellular service if you want to take calls and send texts without having your iPhone on you. You can still make calls and send texts even if you don’t have cellular but you just have to have your iPhone on you/nearby.
Cellular service means you have to call your carrier and let them know you want to add the Apple Watch cellular service to your line (which is an extra $10 per month depending on the carrier)
A:AnswerUnlocked means you could connect it with any compatible cell phone device regardless of your carrier. Yes GPS will still connect to Verizon. GPS+Cellular is the one that will allow you to make calls but you will need to purchase a data plan with your carrier.