covalent bond
Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons by two atoms to produce a mutual attraction. The atoms tend to share electrons, so as to fill their outer electron shells. Commonly covalent bond implies the sharing of just a single pair of electrons. The sharing of two pairs is called a double bond and three pairs is called a triple bond.  Covalent bonding tends to be stronger than other types of bonding.