If the your device has a cracked/smashed/damaged screen then you will need a screen replacement.
You cannot hear it ring or use the handsfree speaker.
If you can't hear the person on the other end of the phone or if the sound is distorted.
Headphone Jack Repair/ Replacement for when your headphones stop working or have no sound from one ear or something is jammed in the port.
The front camera is the one you use in video calling and to take pictures of yourself. Not all models have them.
If your device is running out of power quickly (compared to when it was new) and you are constantly having to put it on charge the battery may need replacing.
When the volume button or buttons feel flat or are not working.
Home Button not responding or requires you to press it too hard.
Replacement back cover to replace your cracked or smashed back cover.
The Charging Port Repair is for when your device won't charge, nor sync to the computer.