In anatomy, an organ is a group of tissues that work together to perform a specific function in the body. Organs are composed of two or more types of tissues, such as muscle, connective tissue, and epithelial tissue. Examples of organs in the human body include the heart, lungs, liver, kidneys, and brain. Each organ has a specific function and is essential for the overall functioning of the body. The study of organs and their functions is an important part of anatomy, as it helps us understand how the body works and how to treat and prevent diseases.