>>14261973"Hard" is the quality of being high on the 'hardness scale', which involves a material being able to sustain its lattice structure formation without deformation under stress from external forces. (Resists scratches, punctures, dents, etc)
Hardness goes hand in hand with brittleness, unfortunately... so the harder something is, the more likely it'll just break all at once than it will have some margin of damage or deformation before failing.
