Dendritic cells are a type of immune cell that plays a crucial role in the immune response by presenting antigens to T cells and initiating an immune response. They are typically found in tissues that are in contact with the external environment, such as the skin, lungs, and intestines. Dendritic cells are known for their ability to capture and process antigens, migrate to lymphoid organs, and activate T cells to mount an immune response against the antigens. They are also involved in maintaining immune tolerance and regulating the immune response to prevent autoimmune reactions. Dendritic cells are an important target for research in immunology and vaccine development.