Ionic bonds involves the electrostatic attraction between opposite-charged ions. imagine a stationery positive charge. when a negative charge is placed in the vincity of the positive charge, there will be attraction between the 2 opposite charged ions. there will be attraction regardless the position of the negative. Hence, ionic bonds are said to be non directional.
In the case of covalent bonds, the bonding electron pair must be between the 2 bonding nuclei. In this sense, the position of the bonding electron pair decides the direction of the covalent bonding.