Today, the term lantern is used to describe many types of portable lighting, but lanterns originated as a protective enclosure for a light source - usually a candle - to make it easier to carry and hang up, and more practical outdoors or in drafty interiors such as passages and staircases where unguarded candles were more likely to be blown out by gusts of air - not just from wind but even opening a door.
Lanterns were usually made from a metal frame, commonly with a hook or hoop of metal on top. Though some lanterns had up to eight sides, five or six was not uncommon but four was the standard, these would be made of some translucent material, now usually glass or plastic but formerly thin sheets of animal horn.
Lanterns may also be used for signaling, as torches, or as general light sources outdoors. Low light level varieties are used for decoration. The term "lantern" is also used more generically to mean a light source, or the enclosure for a light source.