Solution:

Covalent bonds exist in methane, while ionic bonds exist in sodium chloride.

The four strong C–H carbon-hydrogen covalent bonds hold the methane molecule together by sharing electrons.
The ionic lattice of sodium chloride is massive. Ionic bonding occurs when electrons are transferred from one atom to another to ensure that each atom has a complete outer shell of electrons. Sodium loses an electron and becomes Na_⁺, whereas chloride gains an electron and becomes Cl^–.