The strong bonds that form between carbon atoms in graphite are covalent bonds, specifically sigma bonds formed by sp2 hybridization. Each carbon atom forms three strong covalent sigma bonds with three neighboring carbon atoms in a hexagonal arrangement, creating layers of carbon atoms. Additionally, each carbon atom has one free electron that becomes delocalized over the layer, contributing to graphite's electrical conductivity. The layers themselves are held together by weaker van der Waals forces, allowing them to slide over each other easily.