Samsung Galaxy S4 has a 5″ 1080p Super AMOLED display (PenTile 441 ppi), a pseudo octa-core Samsung Exynos 5410 or quad-core Qualcomm Snapdragon 600 (depending on region), 2 gigs of RAM, up to 64 gigs of storage, LTE connectivity, and a 2600 mAh battery. Furthermore, the device features additional features such as floating touch and a 13 MP shooter featuring a revamped camera interface.
Galaxy S4 LTE-A with model number GT-I9506 has got an Android Lollipop update in the form of the CM 12 custom ROM. With Samsung pushing Lollipop OTA for the S5, it will take some time for the S4 to get the official update. Till then you can use this CM 12 ROM. A detailed guide to install this ROM has been given below.