To preserve and prevent decomposition, a body can be embalmed. Stopping decomposition is important when the body will be viewed by family or the community. For viewing purposes, this procedure is used. The mortuary will ask for a recent picture of the deceased to use in preparing the face and clothes to dress the body.
How Embalming Works
The process involves the use of chemicals, primarily formaldehyde. However, today most techniques involve a mix of chemical agents that include glutaraldehyde, ethanol, humectants, formaldehyde and other wetting agents. The deceased fluids are drained, and these chemicals are injected into the arteries, tissues, and even organs of the body.
Steps Of Embalming
Other Resources On Embalming
A great article can be found here.
Also, see funeral options here.