In the benzene ring, the electrons that results in the bonds between the carbon atoms are delocalized. That is, they do not belong to a specific carbon atom. It is this unique feature that enables them to have a bond length between single and double bond lengths.
The top one is different from the bottom because of is curvature shape while the bottom one is a square shape i think the bottom will heat up faster because of the nice even area inside where heat waves can evenly flow
