IOS Incorrect Password when I put in the correct password?

Question

I have had problems with all four iOS devices on my network for three days. It started Thursday (2/12/15) evening, and has been happening ever since. It has to be a relatively global problem because I have a friend in IT who says all of the 40+ iPads on his network have the same problem. My 2 iPhones and 2 iPads will not connect to my WiFi, and when I type in the password (which I know by heart and have verified several times) it says it's an incorrect password. If I go into my router and change the password and then change it back, the devices will connect again. This seemed to have fixed it -- until mid-day today. I haven't tried any resets yet, I wanted to see if anyone else has had a problem. I believe all the devices are on iOS 8. There are 2 iPad 2s, an iPhone 5S, and an iPhone 5C. My network has no problems with my android phone or several laptops. We have never had issues before. The network is secured using WPA2-PSK.

Answer 1

The password is your login password for your account on your own local system. 
This password is not the password associated with your AppleID. 
This password entry ensures that you are confirming that potentially significant changes can be made to your operating system.  This prompt is intended to increase the difficulty for an attacker intent on loading malware onto your OS X system.
The reason you don't have to do this on (older) Microsoft Windows systems (and many of these are running with the Administrator-level access) is also why these (older) Windows releases can tend to get infected; there's no control over who does what within the operating system files and directories.
Newer Microsoft Windows versions can and be and often are configured for something similar to the Mac authentication dialogs with the user account control (UAC) mechanisms; these prompt for authentication before making changes.