Available in a wide range of shapes and styles, which are directly related to the purpose for which they're worn, masks have been found in every culture across the entire galaxy.
Due to the ease with which they are constructed, masks are used in a number of different settings for various, functional purposes. The uses of these items range from keeping sand out of the wearer's mouth and eyes, to uses on the stage for performances, to concealing one's identity while committing crimes, which is the more common use for this item by those less-than-exemplary members of society.
The overall purpose of the mask is the same in most cases: to prevent all but the most sophisticated security devices from being able to detect the identity of the wearer. More often than not, this is achieved through the use of a lightweight helmet and thin, breathable face covering, though more elaborate face coverings have been constructed depending on the specific use for which they're intended.
Despite their fabulous ability of identity concealment, masks offer little to no protection against extreme temperatures or toxic fumes, and they are useless against blaster bolts. Anyone planning on visiting inhospitable environments or entering into combat situations should plan accordingly and wear the proper gear.