The venous system is a network of veins that carries deoxygenated blood back to the heart. It consists of superficial and deep veins, which collect blood from various parts of the body. The veins have valves that prevent the backflow of blood, ensuring it moves in one direction toward the heart. Veins are larger and thinner-walled than arteries, allowing them to hold more blood. The major veins in the body include the superior vena cava and inferior vena cava, which drain blood from the upper and lower body, respectively. Proper functioning of the venous system is essential for maintaining overall circulation and health.