Find my iPhone allows you to track the location of your Apple devices in case it gets lost or stolen. When you locate your device, using Find my iPhone, the device makes noise until it is found and will show you were it is located using the Apple Maps. Find my iPhone has even been used in police investigations however find my iPhone does require to be turned on and connected to the Internet in order for it to work completely. With iOS 8 offers the option to automatically send to the location of the device to Apple when the battery is critically low.
You need to have an Apple ID to access your iCloud account, this is where you will be able to use Find my iPhone. To set up Find my iPhone you need to open settings on your iPhone and tap on iCloud and scroll till you see Find my iPhone and tap on that. Switch on Find my iPhone as well as send last location by default it is turned off. Having this turned on the device will automatically send the location of it to Apple when the battery is critically low. This location will be available for 24 hours for you to see. Now your Find my iPhone is set up on your device.
If you lose your device or it gets stolen there are two methods to using Find my iPhone to locate your device. One way you can do it is using the computer or you can use find my iPhone on another iOS device. Open up your web browser from you Mac and got to icloud.com and login with your Apple ID, then it will show several apps in which you need to select Find my iPhone icon. It will ask for you to reenter your Apple ID password. This will display all devices you have associated with Find my iPhone on your account. From the list of your devices, select on the device that you need to locate. This will then zoom in on the map and show you were the device is located. You can then choose to play a sound, erase the device or lost mode. If you are accessing Find my iPhone though your device you need to have the Find my iPhone app. Sign in with your apple id and tap the device you want. At the bottom of the app there are a couple of options. If you tap on the green car in the lower left hand corner will open up the Maps apps, this assists you in displaying driving or walking directions to your device.
Selecting Play sound will play an audible sound even if the device is on vibrate or silent. This option is suggested if you are located in the same place as the device and just need to hear it and it will continue till the device is found. Lost mode allow you to track your device has been over the last 24hours allowing you to also lock your device and set up a message to display a contact number. This prevents people from access any data on the device but still allowing them to see a number to call. The last option is Erase, which allows you to remotely delete everything on the device. This is a good idea in case you will never be able to recover the device again.
Now that you have it set up you will be able to track the location of your devices in case they get lost or stolen.