Waxes   
Caution
Waxes can be made from many different things, including animals, plants, and even insects (such as beeswax). They are used to thicken or stiffen a product (like lipsticks). It rarely causes an allergic reaction, but it may with very sensitive skin, or if the person is allergic to the source of the wax. At room temperature wax is hard, but softens at warmer temperatures. Wax is insoluble in water, (and only partially soluble in boiling alcohol) [Winter 7th ed pg 546].
Waxes are often used in conditioners to form water-proof films over surfaces, which prevents water loss, which makes them moisturizing and conditioning. They are often used to stiffen products, and to keep them from separating. They are also often used for their appeal as natural products.
According to Hunting (Conditioning), some true waxes are Jojoba oil, Lanolin, Cetyl Esters, Myristyl myristate, and Stearyl stearate. "Wax-like" ingredients are Emulsifying wax nf, Ozokerite, and Paraffin [Hunting (Conditioning) pg 423].
Waxes can be difficult to shampoo out of hair if there is a high concentration of it in a product, such as one containing lots of beeswax, and may build up with repeated use. Wax mixed with clay can be very hard to get out of your hair. Many products made for starting locs contains lots of beeswax, and may be really hard to get out of your hair.

See also: Beeswax Cetyl esters Jojoba oil Lanolin oil Myristyl myristate Stearyl stearate Emulsifying wax NF Paraffin Ozokerite
Source(s): Winter