Incense comes from the Latin word incendere which means to burn. The main ingredients are usually wood pulp, potassium nitrate, water, gum arabic, and aromatic plant materials. Early incense contained nothing other than ground herbs, plant gums, and honey. The term incense refers to the actual substance and not the smell it produces when burning.
Incense is usually used in religious ceremonies, rituals, meditation, aromatherapy or for just hiding foul smells. Now a days, it comes in many different sizes and odors fit for any mood.