Restarting and Resetting iPhone 5c

Restart or reset iPhone
If something isn’t working right, try restarting iPhone, 
forcing an app to quit, or resetting iPhone.
Restart iPhone. 
 Hold down the Sleep/Wake button until the red slider appears. Slide your finger across the slider to turn off iPhone. To turn iPhone back on, hold down the Sleep/Wake button until the Apple logo appears.
Force an app to quit. From the Home screen, double-click the Home button and swipe upwards on the app screen.
If you can’t turn off iPhone or if the problem continues, you may need to reset iPhone. Do this only if you’re unable to restart your iPhone.
Reset iPhone. Hold down the Sleep/Wake button and the Home button at the same time for at least ten seconds, until the Apple logo appears.
You can reset the word dictionary, network settings, home screen layout, and location warnings. You can also erase all of your content and settings.

 Reset iPhone settings
. Go to Settings > General > Reset, then choose an option:
Reset All Settings: All your preferences and settings are reset.
Erase All Content and Settings: Your information, and settings are removed. iPhone cannot be used until it’s set up again.
Reset Network Settings: When you reset network settings, previously used networks and VPN settings that weren’t installed by a configuration profile are removed. (To remove VPN settings installed by a configuration profile, go to Settings > General > Profile, then select the profile and tap Remove. This also removes other settings or accounts provided by the profile.) Wi-Fi is turned off and then back on, disconnecting you from any network you’re on. The Wi-Fi and “Ask to Join Networks” settings remain turned on.