What does Nehemiah 8:16 mean?

So the people went out, brought back branches, and built shelters for themselves—on their rooftops, in their courtyards, in the courtyards of God's house, in the square by the Water Gate, and in the square by the Ephraim Gate. Nehemiah 8:16 - Modern Text Bible

(Everyone joins in, building shelters everywhere, making the festival a visible, communal event.)