Ipad keeps asking me to enter my password for my Apple ID
I have a 4th Generation 16GB 9.7" ipad, iOS 7.1.2, ipad. Woke up this morning and got a message on my iPad telling me to enter my password for my Apple ID to sign into the iCloud. I couldn't do anything else. I couldn't access any other screen. I turned off the ipad. The message was still there. I thought it was a major problem, so I decided to restore the iPad. I connected the ipad with a USB cable to my computer then followed the prompts for backing up and then restoring the ipad. Took about 1 hour. Afterwards, the message was still there.
I finally resorted to entering my password on the ipad for my Apple ID to sign into the cloud. I do not really use the cloud, and don't remember for what purpose that I set up the cloud on this ipad. After entering my password for the Apple ID, I proceeded to delete my icloud account on this ipad.
Was this original prompt a normal message ? Why did I get this message ?
iPad, iOS 7.1.2, 4th Generation 16GB 9.7" screen