How is the electron sea model of metallic bonding different from the band theory? how are they the same? give at least one similarity and one difference between the models

The electron sea model states that the metal atoms are packed, relatively densely, into their crystal structure so that the outer electrons of each metal atom can be shared by all other atoms near enough to share. 

With this "sea of electrons" electrical current, which is a flow of electrons, is best explained because the electrons in a metal are already "flowing" around every metal atom in the crystal and can then freely flow through the metal. it's the same thing with heat. because the electrons are 'free' in metallic compounds and shared by all metal atoms, heat is transferred just as well. Malleability and ductility are explained by this because even though metals are relatively dense, they aren't so dense that they cannot be made to be closer together. because the outer electrons are not rigidly held in place by nuclear charge or strict crystal structure, metals are easily, some more than others, pounded into shape or drawn into wire.