Face coverings are largely intended to protect others, not the wearer, against the spread of infection because they cover the nose and mouth, which are the main confirmed sources of transmission of the virus that causes coronavirus infection (COVID-19). Currently, the best available scientific evidence is that when used correctly, wearing a face covering may reduce the spread of coronavirus droplets in certain circumstances, helping to protect others. Because face coverings are mainly intended to protect others, not the wearer, from coronavirus (COVID-19) they are not a replacement for social distancing and regular hand washing.
Thus, if used correctly and by the majority of citizens in a community, a face covering is a powerful tool in slowing the spread of COVID-19 which can spread predominantly by droplets from coughs, sneezes and speaking. These droplets can also be picked up from surfaces, if you touch a surface and then your face without washing your hands first. This is why social distancing, regular hand hygiene, and covering coughs and sneezes is so important in controlling the spread of the virus.