The back-glass unit includes the flash and wireless charging coil, while battery and screen have separate procedures.
What to check before buying
Rear glass
iFixit treats the back glass as an assembly with the flash and wireless charging coil. A rear-impact repair can therefore involve more than a plain glass sheet.
Battery and screen
Battery replacement calls for new battery and back-glass adhesive. Screen replacement requires new screen adhesive; these jobs use the Plus model's instructions.