A censer (incense burner, perfume burner or pastille burner), is a vessel made for burning incense or perfume in it's solid form. They vary widely in their design and the materials they are made from.
Incense resins require a separate heat source to burn, the heat is traditionally provided by a charcoal disc placed inside the censer.
Burning times of resins can vary with the texture of the material. Finer ingredients tend to burn more rapidly, while coarsely ground or whole chunks may burn gradually as they have less total surface area.