Liquid Crystal Display=LCD it's what makes the picture. On top of that is the digitizer, you can't see it; it records the location of your finger like moving a mouse on a desktop. Most LCD and LED (light emitting diode) displays are "back lighted" with a fluorescent lamp (otherwise you can't see the "picture" on the screen in the dark. What Josh means is the glass screen has the digitizer and it's attached (special glue process) to the top of the LCD. All I've seen so far come complete; you'll see two ribbon cables from the new screen.
Copper grounding tape or other grounding methods are usually for "noise" or EMF suppression. It works the same way as a wrist ground strap for static electricity. Errant electrons are routed away from other components so as not to cause interference or damage. Electronic devices are also regulated as to how much errant EMF/static/noise/electrons not making it to the desired path (however you want to describe it) etc., can be generated and these foils can do just that; "foil" their "escape." (sorry for the pun). Not meant to be a high tech answer.
Had the blank (white) screen problem first then the camera(s) issue. Blank screen fix is hold Power, Up Volume and square button at same time til Apple appears then restart. I hadn't removed the cameras during screen repair, so I went back to check all connections as it sounded like a hardware problem for sure. Found the front side camera plug loose on back of mother board; made sure the "little" spring was not bent and also found the new screen did not have the metal plate glued to it like the original. The spring makes contact with this metal tab which also grounds to the copper foil which wraps the digitizer plug. Used strips of carpet tape (cheap and very sticky) to put all back together; both cameras working. Hope this helps.