Soaps clean surfaces based on the principle of surface tension.
Surface tension is the property of a liquid that makes it behave as if its surface is a stretched elastic membrane. Soaps work by reducing the surface tension of water, allowing it to better penetrate and lift dirt and oils from surfaces.
The soap molecules have a polar (hydrophilic) end that attracts water and a non-polar (hydrophobic) end that repels water. When soap is added to water, the soap molecules surround and lift dirt and oils from surfaces, breaking the surface tension of the water and allowing it to wash away dirt and oils more effectively.
Therefore, soaps clean surfaces based on the principle of surface tension.