To prevent respiratory illnesses that are transmitted airborne to humans, filtering the air we breathe is a key precaution against contamination. Wearing a mask is not the only protection required, read more about other precautionary and protective measures here [insert article link].
Like similar diseases in the past, Covid-19 is a respiratory illness. Scientifically it’s called “severe acute respiratory syndrome coronavirus 2”, or SARS-CoV-2, and spreads airborne when people are close to each other. Invisibly small droplets or aerosols from an infected person’s breath, cough, sneeze or speaking transmit the illness.
To filter these droplets or aerosols from the air that each of us inhales or exhales is why we should all wear a face mask. You can read about the different types of mask here. Also consider who should wear what mask, both from a health perspective as well as to help give everybody the appropriate mask in times of severe mask shortages in some areas.