The word Chuppah or Wedding Canopy means covering or protection. It is intended as a roof or covering for the bride and groom at their wedding. The roof of the Chuppah consists of cloth. Primarily silk, wool, velvet, or cotton which is supported by four poles. It represents the home the couple will build together. You do not have to be religious to have a Chuppah at your ceremony.
Arbors are a decorated arch that the bride and groom stand in front of, instead of under like the Chuppah, and represent no religious meaning. They can be made from anything, though most are usually wood or metal and are then decorated. Most arbors are adorned with flowers or cloth, but can be decorated however you would like.