A joint is an anatomical structure formed where two or more bones meet, facilitating the range of motion within a skeletal system. These connections are complex tissues, often involving cartilage, ligaments, and synovial fluid, which serve to reduce friction and provide stability. Joints are generally categorized based on their structural complexity and degree of movement, ranging from immovably fused joints to highly mobile synovial joints. The specific type of joint dictates the mechanical functions allowed, providing the body with the necessary mobility for complex actions while maintaining structural integrity.