Lymph system is a network of organs, lymph nodes, lymph ducts, and lymph vessels that make and move lymph from tissues to the bloodstream. The lymph system is a major part of the body’s immune system. Lymph nodes are soft, small, round- or bean-shaped structures. They usually cannot be seen or easily felt. Lymph nodes make immune cells that help the body fight infection. They also filter the lymph fluid and remove foreign material such as bacteria and cancer cells.