What is the difference between a cedar shake and a cedar shingle?

Cedar shakes are split on one or two sides. They are thicker than shingles and have a 'rougher' look. Shingles are sawed on both sides. The most significant difference is the amount of exposure. An 18" shingle is applied at 5 1/2" to the weather while an 18" shake is applied at 7 1/2" to the weather. Shingles applied at 5 1/2" become a 3 ply roof which means that there are 3layers of shingles at any location on the roof. Shakes are 2 ply. Shakes are layered with felt between each layer, thus having two layers of felt at any location. No felt is required between each layer of the shingle application. Another difference is shakes have a split face, which gives a rustic appearance. The exception is the tapersawn shake, which looks like a thick shingle.