There are two basic types of bangles: a solid cylinder type; and a split, cylindrical spring opening/closing type. Primary distinguishing factor for these is the material that is used to make the bangles.
Although now seen as a fashionable jewellery accessory, bangles are traditionally part of Indian jewellery worn mostly by South Asian women, especially Hindus. They are usually worn in pairs by women after marriage to signify matrimony, one or more on each arm. It is tradition that the bride will try to wear as many small glass bangles as possible at her wedding and the honeymoon will end when the last bangle breaks.
Examples of modern bangles made today:
mixed selection of bangles