What type of bond is formed when a sea of electrons moves freely among tightly packed cations?

You describe a $\text{metallic bond.........}$
The old story, metallic bonding results from $\text{positive ions in an}$ $\text{electron sea,}$ and each metal centre contributes an electron or so to the metallic lattice, and thus bonding is delocalized over the entire lattice. Given that the metal nuclei can move with respect to each other, WITHOUT disrupting the non-directional, metallic bond, this rationalizes metallic properties: $\text{malleability}$; $\text{ductility}$; $\text{conductivity to electricity and heat........}$
PS What do $\text{malleable}$ and $\text{ductile}$ mean? And why should these properties be important with regard to tool-making?