One of the criteria that can be used to compare the two devices is practicality. This includes the size and structure of the devices, battery life, storage, etc.
Looking at size comparisons first, the Galaxy S4 is 7.7mm thick, with a 5-inch 1080p Super AMOLED (which allows for highly saturated color) screen and plastic rear and exterior; while on the other hand, the iPhone is 7.6mm thick with a 4-inch 1136 x 640 pixel IPS (which allows for vibrant color and picture from nearly any angle) screen and an aluminum frame and glass inlays, according to TrustedReviews. This indicates that the iPhone is thinner with a smaller screen, while the Galaxy is thicker, has a much larger screen, and sharper display.
While it is thicker by only .01 mm, the Galaxy has a curvier, smoother body, while the iPhone has more relatively severe edges due to its angular aluminum shell. Thus, the Galaxy is more attractive in that aspect. Nevertheless, the Galaxy is also 1 cm wider than the iPhone making it harder to hold because of its wider size. Thus, as a bigger phone the Galaxy could pose to be less practical because it would be harder to carry, both in-hand or in-pocket. However, the larger sceen allows for easier viewing and gaming. Likewise, while the iPhone is more angular in-hand, it is easier to hold because it is only longer than its predecessors, rather than wider. It also features a fingerprint scanner home button that is incredibly useful and practical: instead of typing in one's password, a simple fingerprint scan will do the job.
The size of the phone is not the only criteria to decide practicality; battery life and storage space are also good indicators.
According to the Verizon Wireless site, the Samsung Galaxy S4 has 288 hours of standby time or 17 hours of usage time at its disposal and is available in 16 GB and 32 GB (32 GB not available at Verizon) versions of the device. The iPhone, on the other hand, is able to utilize 250 hours of standby time or 10 hours of usage time while having 16 GB and 32 GB versions of the device available. Although these data would indicate that the Galaxy has better battery life, its issues with battery have been its biggest issue. There have been reports of batteries draining down quickly or even of them swelling up. Nevertheless, an advantage Samsung's products have over Apple's in this area is the removable battery. The Galaxy S4 contains a replaceable 2600mAh battery. This makes it easy to replace the battery if any problems were to arise unlike with the iPhone, whose entire body encases the battery and hardware making it almost impossible to access and highly impractical.
Nevertheless, practicality is not the only criteria one can use to evaluate these two products.