"other" usage

I have a 13GB iphone 5s and I am trying to manage my storage; however, the largest amount of storage being used is in the "other" section at about 3.48GB. I have been doing some research and have had no luck finding what this "other" section is and how I can minimize its prominent usage on my phone. I'm not sure if 3.48GB is a normal "other" usage or if my phone is suffering a different problem. I will take any suggestions at this point. Thanks!