The Center for Disease Control and World Health Organization advise the use of simple cloth face coverings to slow the spread of the Covid-19 virus, and help people who may have it, but do not know it, from transmitting it to others. Cloth face coverings can be used as an additional public health measure.
Masks don't make you invincible, and they absolutely can't replace good hygiene, but along with washing your hands and practicing social distancing, they can help.
Whether or not to wear a face mask in the wake of Covid-19 is a hot debate. Do they really work? Are they just for public perception? A mask acts as a barrier to prevent the spread of the virus, but it only works when worn correctly.