Vertical colored lines on broken screen -- is it just my screen?
The glass and screen are fused together at the factory. Replacement kits, such as those sold by iFixit, include the glass, LCD/digitizer (screen), and other parts. Cell phone repair stores/kiosks use this same type of thing when repairing devices.

It's possible that additional parts inside the device were damaged, but it's also just as possible (and probably more likely) that the screen is simply too heavily damaged to display anything.

Also of note - Apple will fix a broken screen for $129 out of warranty, so keep that in mind when comparing prices if you move forward with repairs.