What is Dao (Tao)? Who is Laozi?

People think about Tai Chi diagram when mentioning about Taoism (Daoism). Who invented Tai Chi? In order to explain I-Ching, Confucius invented the name of Tai Chi for the origin of universe, which means "All That is". So Tai Chi is the universe. Confucius said Tai Chi is big without outside and small without inside. Since there was no vocabulary in Chinese to explain the Tai-Chi. The founder of Taoism, Loazi found the best Chinese word for Tai-Chi is Tao (Dao). Tai Chi is a top level of Yin Yang. The view from opposite angel is that one Yin and one Yang form the Tao. Laozi wrote Tao Te Ching, which is the bible of Taoism. Therefore, Dao is Tai Chi.