Many of us are familiar with CV system, right? Breathing, lungs, heart pumps blood, blood vessels and exchange of the gases- oxygen (awesome), carbon dioxide (waste). Allow me to point out that the CV primarily concerns itself with Red blood cells because they are the guys who love to transport Oxygen around.
The lymphatic system, includes lymph vessels that carry lymph fluid. Lymph fluid transports waste, as well has transports fats from the digestive system, and in the process notices if there are unwanted antigens in your body and whether or not an immune response is necessary. The fluid and materials are filtered out in the lymph nodes and then the clean lymph returns to the bloodstream via the subclavian viens or thoracic duct. Lymph travels ONE direction- toward the base of the neck, ultimately ending up in the 'thoracic duct'.