Here's why:

* Hydrophilic means "water-loving". These substances have a strong affinity for water molecules. They tend to be polar, meaning they have a positive and negative end, which allows them to form hydrogen bonds with water molecules. This attraction overcomes the forces holding the substance together, causing it to dissolve.

* Hydrophobic means "water-fearing". These substances are non-polar and have a weak attraction to water molecules. They are more likely to clump together than dissolve in water.

Examples of hydrophilic substances:

* Sugar

* Salt

* Alcohol

* Acids

Examples of hydrophobic substances:

* Oils

* Fats

* Greases

* Wax