Expectedly, Apple is a different kind of cell phone manufacturer and introduces only a few new models per year, all named iPhones. Shoppers considering Iphone models should know that they typically come with differences that one would not expect in most smartphones. For instance, iPhones generally have fixed batteries that can't be changed by the owner and don't expect standard connectors like HDMI or a USB charger, Apple prefers to develop its own connectivity standards.
Also, do not expect the possibility to add microSD cards, but iPhone models are available with high amounts of on-board memory, including 32 and 64GB flavors. With the advent of the iPhone 5c, Apple started targetting the low cost market. Upcoming and new phones are at the top of the list.
More resources about Apple smartphones:
How Big A Apple Fan Are You? Let People Know...