Shields are handheld (or wrist- and/or forearm-mounted) pieces of personal armour of various shapes and sizes, typically made of wood and/or metal. Shields are typically used for intercepting attacks, both in close combat (i.e. deflecting or blocking blows from handheld weapons) as well as from incoming projectiles (i.e. arrows or javelins). Shields provide means of active block (as opposed to passive protection such as coats of armour, helmets etc.); shields are very much weapons themselves and are (and were historically) used as such. Depending on historical period and type of shield, skilled combatants were able to deliver various blows, hook or pin opponents' weaponry or body parts, conceal movements of their next attacks and much more.
Shields were commonplace defense pieces in Tolkien Mythology. They were defense devices used by the vast armies of Sauron, the Goblins of Khazad-dûm, the Uruk hai of Isengard, the Elves and the Men of the West. Most symbols were used on shields such as red eyes, crescent Moons, spiders, snakes, trees, hands, Suns and Horses. Servants of good and evil alike made and used them for use by soldiers mounted on horseback, or on foot. The warriors of both Rohan and Gondor used shields to protect themselves.