What are the main differences in sound and construction between a glockenspiel, xylophone, and marimba?

The main differences between a glockenspiel, xylophone, and marimba are in their sound and construction. A glockenspiel has metal bars and produces a bright, high-pitched sound. A xylophone has wooden bars and produces a sharp, percussive sound. A marimba has wooden bars like a xylophone but is larger and produces a warmer, more resonant sound.