Why are ionic bonds and covalent bonds different?
Well, one is a non-directional bond..............
Well, the one is a non-directional bond that derives from the interaction of like and unlike charged particles. And t'other is a strongly directional bond that results from the sharing of electrons BETWEEN adjacent nuclei. Each covalently bound atom contributes one (or more) electrons to a region of high electron density BETWEEN the atoms, to which the positively charged atomic nuclei of the participating atoms are attracted.
So the take home message is still the same as the elementary description:
As a result, ionic compounds tend to be non-molecular, with bonding interaction thruout the entire solid. Covalently bound materials CAN BE non-molecular, but this bonding generally allows formation of discrete molecules.
You should able to think of some examples of each form of bonding interaction in order to illustrate your understanding.