Metallic bonding is the type of chemical bond characterized by the delocalization of valence electrons within a solid material. In this structure, valence electrons are not associated with specific individual atoms but rather form a mobile "sea of electrons" that surrounds a lattice of positively charged metal ions. This electron delocalization is responsible for many characteristic properties of metals, including high electrical and thermal conductivity, as the free electrons can move easily under an applied potential. Furthermore, the non-directional nature of this bonding mechanism accounts for the high malleability and ductility observed in metals, allowing them to deform under pressure without fracturing.