Tissue types are groups of cells that work together to perform specific functions in the body. There are four main types: epithelial tissue, which covers surfaces and lines cavities; connective tissue, which supports and binds other tissues; muscle tissue, responsible for movement; and nervous tissue, which transmits signals throughout the body. Each tissue type has unique characteristics and roles. For example, epithelial tissue can be found in the skin and organs, while muscle tissue includes types like skeletal, cardiac, and smooth muscle. Understanding these tissue types is essential for studying anatomy and physiology.