Answer is: chemical bond (two main type: covalent and ionic bond).
Covalent bond is a chemical bond where atoms share of electron pairs.
Ionic bond forms when a cation transfers its extra electron to an anion who needs it. For example compound magnesium chloride (MgCl₂) has ionic bond (the electrostatic attraction between oppositely charged ions). Magnesium transfers two electrons (became positive cation) to chlorine (became negative anion).
For example, NaClO (sodium hypochlorite) contains both ionic and covalent bonding, ionic bond is between sodium and chlorine and covalent bond is between chlorine and oxygen.
