Why is a building called a building when it is already built?

Why is a building called a building when it is already built?

well
building is called as building even after its built because there will lot changes keep going evryday in building like one who lives in that building keeps growing both physically and mentally he is building his own personality and identity that is building process
tere goes change in position onm equ7ipment people etc lots and lots of changes in building evry day evry moment so its a building process either positive attitude or negative so its called building even after its built