(i) O/W Emulsion : It is a colloidal system in which dispersed phase is oil and dispersion medium is water and type of colloidal is emulsion.
(ii) Zeta potential : The potential difference between the fixed layer and the diffused layer of opposite charges is called the zeta potential.
(iii) Multimolecular colloids : On dispersion of a substance in the dispersion medium, a large number of atoms or smaller molecules of the species have size in the colloidal range. The species thus formed is called multimolecular colloid.