Cedar and redwood are two similar lumber species that are often used in outdoor projects because of their ability to withstand the weather and the environment. Redwood is not as commonly available as cedar and commands a higher price.
Cedar and redwood are popular for use in outdoor projects such as decking and furniture. The oils in these two types of wood make them naturally resistant to insect damage and decay from environmental factors. Redwood is often left unfinished, while cedar benefits from a protective oil finish.
Cedar is structurally stable, retaining its structural dimensions regardless of environmental effects. The cellular structure of the wood makes it resistant to breakage and cracking while still retaining a reasonable weight. Redwood is also a good structural lumber, though with slightly less strength.
Redwood heartwood has a consistent reddish color and consistent grain that's prized by architects and builders. Cedar is more varied in grain and color, and requires careful shopping in order to match the lumber used in a project.