Like many things in the world, drum sticks come in all shapes and sizes, to suit a variety of applications. The most common types of drum stick are brushes, mallets, hot rods, and the classic style, which itself comes in many different sizes.
Each style has its own unique sound and can be used to give a bit of variety in drum tone. Brushes are as the name suggest made of many strands (usually metal) typically used for jazz, to soften the sound to a more gentle relaxing tone. Hot rods are also made of many strands but made from wood, and the strands are bound together. This gives much more of a crack, creating a multiple attack sound. Mallets give a soft bouncing sound.