Aluminum foil is ideal for wrapping odiferous foods, helps seal out oxygen, and is good for wrapping items that are to be reheated in the oven, but it is impossible to view the contents of the package due to foil's opacity, it reacts with acidic foods and it cannot be used in the microwave. Plastic wrap is transparent, doesn't react with acidic foods and can be used in the microwave.
Aluminum foil is best at protecting foods from the effects of light and oxygen, which can damage food. Because it also keeps moisture out of food, it is ideal for freezing food. Wrapping foods in both plastic and foil prior to freezing provides maximum protection. Aluminum foil must never be used in the microwave due to the risk of fire.
Plastic wrap forms airtight seals on containers. Because it's transparent, users can view the contents of the containers, which is impossible with aluminum foil. Plastic wrap is best for wrapping acidic foods because aluminum foil reacts with acids to create a harmless but unsightly blue residue. Plastic wrap can be used in the microwave, unlike aluminum foil, but it needs to be at least an inch away from the food as the heat from the food can cause the plastic to melt.