[true, they stop YOU (the person wearing the mask) from transmitting what YOU have to others. But they do NOTHING to stop YOU from getting the Virus from others.]
https://www.businessinsider.com/types-of-masks-used-for-coronavirus-outbreak-n95-surgical-2020-3
there’s a link to the different types of masks and what they are good and not good for.
Most of the masks you see are the disposable surgical type and are basically useless to prevent getting infected, but can help with not infecting others.