When a new iOS is released, you can instantly update any of your iOS devices (iPhone, iPod, iPad), but in the Android world, the different phone manufacturers have almost all installed their own customised version of Android. So when google releases a new Android version, you will have to wait for your phone manufacturer to make a customised version of it for your phone. Sometimes you’re even out of luck if the manufacturer decided they wont update your particular model!!
This needs to change… Google got to get all these manufacturers to install one unified version so updates can happen a lot faster!