One is attracted to the soil, the other is attracted to water. The chemical compound that s attracted to water is called a hydrophile. Its job is to surround the soil. Likewise, the chemical compound that s attracted to soil is called a hydrophobe. Its job is to break soil into smaller pieces so it can be surrounded by the hydrophile.
Every cleaner needs a solvent to dissolve soil.
The most common solvent is one you might not even think of, water. Some solvents, such as mineral spirits, work great on petroleum soils, like tar and grease, and may be necessary on surfaces that might be damaged by water. Although expensive, dilimoneen is a safe solvent to use throughout the car. Chemists modify the hydrophile and hydrophobe molecules to change the characteristics of a surfactant. Penetrating and wetting allows water to surround soil so it can be removed.