An Android device has a project codename associated to it.
jfltexx is the codename for Galaxy S4 phone.
jfltevzw is the codename for Galaxy S4 VERIZON variant.
Similarly, different Android devices will have different codename.
Your phone Galaxy S4 SM-S975L (net10) will also have a codename associated with it.
How to get codename of an Android phone:
Run the following command on a PC while your phone is connected:
$ adb shell getpro ro.product.device
You need USB debugging enabled on your Android phone and the ADB command installed on your PC to be able to execute the above command.