Like common influenza, coronavirus is an airborne disease and spreads when an infected person is in the vicinity. The fastest way it spreads is through the droplets expelled when an infected person is sneezing or coughing in a healthy person’s company.
Another way it spreads is by aerosols (small airborne particles), which can be released by natural respiration.
Consequently, face masks are considered by many to be an important measure to delay or avoid the spread of the aforementioned virus. These face masks intercept particles which cause disease from entering your respiratory system.
Regions affected by Coronavirus disease have for this purpose institutionalized mandatory public use of masks. For example, every person in the district of Wuhan (the epicenter of the virus) accompanied by people in South Korea and Japan must wear a mask in public on a mandatory basis.