Joss sticks are long, narrow sticks of incense, which are either held in two hands while praying or placed in a sand filled container and burned in various personal, family, and public religious rituals.
First, just to clarify, the word joss isn’t Chinese. It comes from the Portuguese word for god, deus. Nevertheless, joss is now the standard term used and if you wanted to buy some in a local Chinese grocery, for example, it’s what you’d look for.
The Chinese have been using incense to assist in communicating with the supernatural as far back as 2,000 BC! Apparently, early Chinese used aromatic herbs and other plants, such as sandalwood, to burn. However, although these are called incense, today it is common today to use a non-fragrant material in the joss sticks which are used for prayer purposes. It’s not the fragrance that’s important in the ritual so much as the smoke given off by the joss sticks as they burn. The smoke rises upwards, carrying the prayers to the gods or ancestors. There are fragrant incense sticks and these can also be used for praying.