a shock wave is propelled outward by the explosion itself; a shock wave is part of the explosion, the actual gases produced by the explosion being pushed outward. a shock wave moves faster than sound and is usually fatal if you are struck by one.

pulse waves move at the speed of sound and are not propelled by the explosion. an air compressor tank rupturing would produce a pulse wave. pulse waves alone are not fatal to humans, though you definitely feel them and hear them.