As a sign of respect
In Chinese society, the younger generation always shows their respect to the older generation by offering a cup of tea. Inviting their elders to go to restaurants and having some tea is a traditional activity on holidays. In the past, people of lower rank served tea to higher-ranking people. Today, as Chinese society becomes more liberal, sometimes parents may pour a cup of tea for their children, or a boss may even pour tea for subordinates at restaurants. However, the lower-ranking person should not expect the higher-ranking person to serve him or her tea in formal occasions.