Incense is composed of aromatic plant materials; often combined with essential oils. The forms taken by incense differ with the underlying culture; and have changed with advances in technology and increasing diversity in the reasons for burning it.

Incense can generally be separated into two main types: "indirect-burning" and "direct-burning." Indirect-burning incense (or "non-combustible incense") is not capable of burning on its own; and requires a separate heat source. Direct-burning incense (or "combustible incense") is lit directly by a flame and then fanned or blown out; leaving a glowing ember that smoulders and releases fragrance. Direct-burning incense comes in several forms; including incense sticks (or "joss sticks"); cones; and pyramids.