Hi! I am having difficulty grasping what band theory actually is, especially what the bands are and the energy gap between them. Are they probabilities? Shared electrons between atoms such as in metallic bonding? What is the difference between the conductor band and the valence band? I think I read somewhere that the conductor band is the outermost band, but shouldn't that be the valence band as it comprises of valence electrons? And finally, does someone have photos or videos for visualization purposes? I'm learning it on a very basic level by the way.