Final answer:
The shiny side of aluminum foil is used to reflect heat, while the dull side is more absorbent. Both sides are safe to use and won't affect the safety or taste of the food.
Step-by-step explanation:
The shiny side of aluminum foil is used to reflect heat, so it is often recommended to face the shiny side towards the food. The dull side is more absorbent, so it can help retain moisture in the food. However, it's important to note that both sides of aluminum foil are made of the same material, so they are safe to use and won't affect the safety or taste of the food.