Young Indian Girl With Pigtail And The Red Bandanna

Bandanas are most often used to hold hair back, either as a fashionable head accessory, or for practical purposes:
Cowboys would typically wear bandanas around their face to keep dust out and keep the scent of their horse's manure away as they traveled slowly.
Outdoor workers, such as farmers and cowboys, wear them around the neck to wipe the sweat off their faces and keep dust out of their collars.
Wildland firefighters wear them over the mouth and nose to lessen inhalation of dust and fumes.