About iPhone 5 Digitizer
It's fairly easy to accidentally crack the screen of your iPhone, and, depending on the amount of damage, if you've only broken the screen and digitizer you might still be able to use your phone as you may still be able to see the screen behind the cracks.
However, any damage to the screen and digitizer on your iPhone 5 makes it more likely that the LCD behind will be broken, and therefore it is important to get your cracked screen and digitizer fixed before your phone becomes unusable. If you are purchasing an iPhone 5 with a broken screen and digitizer you might want to buy a new screen and digitizer at the same time.
The way the iPhone 5 is made means that to replace the screen and digitizer you need to get a new front panel too, so make sure you select the same colour as your model. The original iPhone 5 comes in black or white, and there is also the iPhone 5C range which comes in a variety of colours. It is also important to make sure that you are getting a screen and a digitizer. The screen is simply the glass, the digitizer is the part of the phone that detects your touch so you won't be able to use your iPhone 5 without one.
As you can imagine replacing the screen and digitizer on an iPhone 5 requires special tools - these are readily available though and often come in a package with the screen and digitizer itself.