Skeletal muscle is one of the three types of muscle found in the body. The other two are smooth muscle and cardiac muscle. Skeletal muscle is similar to cardiac muscle because of its striated appearance and contractibility. It is unlike cardiac muscle because it is controlled my the somatic nervous system. That basically means that you can voluntarily command your muscles to contract and create movement via neurons.
These muscles are able to move the body because they are attached to bones by collagen fibers called tendons. When the muscles contract they move the bones like levers.
Movement is the main function of this type of muscle. Some other functions are creating body heat, holding body posture, and storing nutrients.