Which is the most accurate description of ionic and covalent bonding?

Ionic Bonding: 
This type of bonding occurs when atoms want to fulfil their valence shells by taking/giving electrons to other atoms. This, leads to completed valence shells in most cases and ionisation of both elements. The opposite charges cause the elements to stick together because opposites attract. 

Covalent Bonding: 
This type of bonding occurs when electrons are shared between atoms to each fill up their own valence shells by sharing. The balance between the attraction forces and repulsion forces between the shared electrons is called covalent bonding. 

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