Here's why:

* Storage: The mouth holds food temporarily while it's being chewed and mixed with saliva.

* Moistening: Saliva, produced by glands in the mouth, helps to moisten food, making it easier to swallow.

While the stomach also plays a role in food storage and digestion, it primarily focuses on breaking down food with acids and enzymes. The mouth is the initial stage where food is first encountered and prepared for further processing.