So what are the common specs of a phone??? Processor, Display, RAM and everything...Lets see what S4 has to offer :
Display: 5 inch Full HD Super AMOLED (1920 x 1080) display, 441 ppi
Processor: 1.9GHz quad-core processor / 1.6GHz octa-core processor (will differ depending on market)
OS: Android 4.2.2 Jelly Bean RAM: 2 GB
Rear Camera: 13 Mega pixel Auto Focus camera with Flash & Zero Shutter Lag, BIS
Front Camera: 2 Mega pixel camera, Full HD recording @30fps with Zero Shutter Lag
Internal Storage: 16/ 32/ 64 GB User memory + microSD slot (up to 64GB)
Battery: 2,600 mAh
What's New??? Just the upgraded hardware...sort of, Lets find out what new features are...
Most exciting new features, however, are Samsung's suite of user-tracking functions, including its new Smart Pause, Air View, and floating touch controls. The Galaxy S4 uses its front-facing camera to detect when a user looks away from the video they're watching and automatically pauses playback. Air View, on the other hand, allows users to scroll through pages with a wave of their hand. Floating touch takes Samsung's S Pen concept and applies it to your fingers, allowing you to point and hover over an item to view it.
New camera functions Dual Shot, Eraser, Drama Shot, and Sound & Shot. Dual Shot allows you to capture images from both the front and rear cameras simultaneously, while Eraser captures multiple frames so that you can remove unwanted subjects, Drama Shot composites moving objects for action shots, and Sound & Shot captures five seconds of images and audio before the capture button is pressed.
We have list down all features below...Watch the Hands On Video from AndroidCentral.
Drama Shot: Turns a string of photos into a timelapse.
Dual View: This lets S4 owners use both the front and rear cameras at the same time, which can also be used during video calls.
Group Play: Lets people share media between one another without Wi-Fi. Also syncs up music playback between devices.
Story Album: Pulls together photos you've taken and can be turned into photo albums.
S Health: Uses the S4's onboard sensors to track and estimate personal fitness.
S Translator: Translates voice or text within certain applications, and works offline.
S Voice Drive: Takes voice commands while driving, and turns up the size of text. Works over Bluetooth with Bluetooth-enabled cars.
Samsung Optical Reader: Scans business cards and QR codes for text.
Samsung WatchON: Uses the built-in IR to control other electronics like TVs and set top boxes.
Smart Pause: Pauses video playback when it detects that you're not looking. The same technology works for scrolling up and down on a Web page, or e-mail.
Here is Hands on Video From AndroidCentral :