CCC 1184
Christian Mystery›SECTION ONE THE SACRAMENTAL ECONOMY›CHAPTER TWO THE SACRAMENTAL CELEBRATION OF THE PASCHAL MYSTERY›IV. Where is the Liturgy Celebrated?
The chair (cathedra) of the bishop or the priest "should express his office of presiding over the assembly and of directing prayer." The lectern (ambo): "The dignity of the Word of God requires the church to have a suitable place for announcing his message so that the attention of the people may be easily directed to that place during the liturgy of the Word."