Muscles, specifically skeletal muscles, are vital for various functions in the human body. They allow for movement, generate heat, and support bodily processes like breathing and digestion. There are approximately 600 muscles in the body, each with a specific role and function. These muscles are classified into three types: skeletal, smooth, and cardiac. Skeletal muscles, attached to bones, manipulate and control movement, while smooth muscles assist with functions like digestion. Cardiac muscles are unique to the heart and facilitate its pumping action. Overall, muscles play a crucial role in maintaining the proper functioning of the human body.