Hi, Here is Sandeep, Actually I am facing issue with my iPhone 5s.

Did you full your phone's storage all the way up? If that's the case, it could cause that issue, but it is more unlikely. You could more likely be facing a Firmware fail (which I don't know the solution to) or you somehow corrupted iOS. If your phone's iOS is corrupted, you lost all of your data. Try putting the phone into recovery mode. If it works, then plug it into a computer and restore it. If that doesen't work, then you can put your phone into DFS mode, plug it into a computer and restore it. You can also use some recovery tool to get some of your data back, but you most likely won't get all of your data back and it sometimes it won't get any of your data back.

iOS stands for: iPhone Operational System.