The way of sky is 1Mu and it is a Mudo(巫道) that knows the heaven. It is a life that knows that the source of all things is in heaven and lives according to the harmony and order of heaven. Knowing the heavens means knowing the will of heaven, and that means is the spirit of the Hongik Ingan( who benefit people widely.
The way of people is 2nd Mu and it is a Mudo(舞道) that knows the people. Mudo(舞道) of knowing people refers to a communal life that lives together, not that you and I exist separately, but that it is a life where everyone is together, and that we are all connected as one.
The way of the earth is 3th Mu and it is a Mudo(武道) that distinguishes between what to do and what not to do. It refers to conformity and harmony to maintain the community, and moderation and norms for the order of the community.