Get ready... What is an operating system?

Operating systems are listed in order of latest release.

Microsoft- a multinational corporation that develops, manufactures, licenses, supports and sells computer software, consumer electronics and personal computers and services. Apple- a multinational corporation that designs, develops, and sells consumer electronics, computer software and personal computers.

What's my Operating System?

Device: How to determine OS:
iOS - iPad, iPhone, iPod Touch Go to Settings>General>About
Mac Computer/Laptop From the Apple menu (top left corner), choose About This Mac. Your version of OS X appears directly below “OS X”
Android Tablets & Smartphones Settings>About Phone (scroll all the way down)>Android Version
Kindle Fires Drag your finger down from the top, and choose Settings>Device Options>System Updates
Nook Tablets Tap the Settings icon in the Status bar at the top of your screen, tap on All Settings>Device Information, and check your Software version
Windows Computers/Tablets Visit Microsoft Support page
Windows Phone & RT Tablet Visit Microsoft Support page
Chromebook Navigate to device's browser, type this in the browser: chrome://help/ and hit enter or go
MP3 Player It depends. Visit What's My OS? for more information.
Standard eReaders (e-ink, Nook, Kobo) It depends. Visit What's My OS? for more information.