Answer:
It acts as a filter to prevent as much germs, or chemicals/substances, as possible from entering your immune system through your breathing. This is whether you're in a lab or in a grocery store with a pandemic going around. Not only does it protect you but it also protects those around you by filtering any germs you may already have in your system and preventing them from passing on to another person. That is why you should always wear your mask over your mouth and your nose.
Explanation:
Hope this helps. Have a great day. May it be filled with joy and happiness. Please, stay safe and wash your hands.
