A:Answer Depends.
If you are already in the Android ecosystem (Samsung, LG, Motorola, some Nokia, OnePlus, anything that isn't Apple, Amazon or Microsoft) then all you have to do is sign into your Google account and you can restore from another phone's backup to tell the phone what data it needs to download. If you are in Samsung's ecosystem already the process goes at double the speed because it also downloads data from Samsung servers.
If you are on iOS, a portable Windows OS or Amazon Fire OS then you will have to rebuy your apps. That is unfortunate, but its because of licensing/royalties.