The Samsung Galaxy S4 Active is a variant of the Samsung Galaxy S4 which includes dust and water resistance. It has a 5 inch Super AMOLED touch display with a 1080 by 1920 pixel resolution, up to 16GB of internal storage which can be expanded through microSD, an 8 megapixel camera capable of 1080p HD video capture, a secondary 2 megapixel camera for video calls, 4G LTE connectivity, NFC, and is powered by a 1.9GHz quad-core processor with 2GB of RAM.On the software side you get the latest version of Android 4.2 Jelly Bean coupled with Samsung's TouchWiz UX interface and several of the company's custom applications.
You can read the detailed review of the Samsung Galaxy S4 Active on PhoneArena