The word anonymity is derived from the Greek word ἀνωνυμία, anonymia, meaning "without a name " or "namelessness". Wikipedia and the artist Magritte have it correct. There are so many kinds of masks, and each can worn for a different purpose.
Festive masks are worn by children from all over the world.
Doctor and nurse don masks to keep nasty germs from us.
Masks for religion.
Superheroes use masks.
Artists often explore masks in their art--and have for thousands
of years. Man Ray did some of his most elegant and provocative work using models and masks, often with a fetishistic accent.
by Man Ray
Hands hide our face. Sunglasses a mask.
What is your mask?
Are we hiding from each other, ourselves, the world?