Samsung seems to be following a new strategy for releasing its flagships in 2013. Galaxy S4 as the latest flagship of Samsung is not just a phone, and it is actually a collection of phones. This strategy is rumored to be continued for Galaxy Note series too and we should expect three different versions for the latest iteration of Note series in the near future.
Galaxy S4 in different versions (Powered with Snapdragon 800, or LTE), Galaxy S4 mini (Dual SIM is available too), Galaxy S4 Active, Galaxy Zoom, and Galaxy Mega are the members of this collection so far.
In this Infographic we have illustrated the main features of each of these phones. (click to see the infographic is real size: Galaxy S4 Collection)

Galaxy S4 Collection