The idea of having an Apple on your wrist is one that many people have looked forward too since the idea was first leaked. The Apple Watch is considered an accessory to your iPhone at this time. The version of iPhone you need to operate the watch at its full capacity is an iPhone 5 or newer.
Basically you need your iPhone to be on and connected to the internet by some means for you to send messages, surf the net or make phone calls from your Apple Watch. This might change in the future, but for now you need an operational iPhone to use these systems on your Apple Watch.
There are a few independent systems on your Apple Watch you can still access when your iPhone is off or left behind. This includes the playing of music. You can access the 2 GB storage area on your watch that is reserved for this. This requires for you to first sync the music on your iPhone with the watch. You also need to press Force Press and then Source for the music to be accessed. Since the watch does not have speakers, you will need a set of ear phones to actually listen.
If you are exercising there are two different programs on the watch to help you monitor this activity. This includes the monitoring of your heart rate, pace, distance covered and an estimate on the amount of calories you burned. If you have your iphone on you the tracking of your path can be done with the GPS app.
The Apple Watch also functions as a standard watch. You can also retrieve pictures from its memory and use Apple Pay if you have previously set up your account to permit access by your watch.
The Apple watch is a great accessory for those who do not want to hold their mobile device in their hand but instead just look at their wrist. In time the need for an iPhone in operating the watch will be removed as a restriction.