Smudging is the burning of certain herbs to create a cleansing smoke bath, which is used to purify people, ceremonial and ritual space, and ceremonial tools and objects.There are different ceremonies and rituals that can be done.
The burning of herbs or incense is a practice held sacred by many indigenous cultures. It is a ritual for cleansing, purifying and protecting the physical and spiritual bodies. The effect of the smoke is to banish negative energies.
Many differing cultures and peoples have their own methods and herbal mixtures for this purpose. Smudging, done correctly, can bring physical, spiritual and emotional balance.
The term Smudging originated in the Native American culture. Native American Indians use a variety of smudging mixtures. In olden times, the end of the smudge stick or braid was lit from the central or cooking fire.
Not everyone views the practice of smudging in the same way and different herbs may be used for different purposes.
The information above was found on http://www.crystalinks.com/smudging.htm