Narthex/Vestibule
An entry space, foyer, or anteroom of a church between the door and the nave. The term is from the Greek for a "small case." Historically, the narthex was an enclosed vestibule or porch of a basilica. Catechumens and penitents stood in the narthex during the service. It also may serve as a place for the gathering and formation of processions and a place for people to wait before services begin.
Nave
The place in the church building for the congregation. It is between the sanctuary and the narthex or entry of the church building. The term may be derived from the Latin navis, "ship," which was an early symbol of the church.
Chancel
Area of the church set apart for the altar, lectern, pulpit, credence table, and seats for officiating and assisting ministers. It may also include the choir. The chancel is typically raised somewhat above the level of the nave, where the congregation gathers. The chancel may be separated from the nave by a low screen, rail, or open space. In some churches, the congregation may gather on three sides or in a semicircle around the chancel.
Sanctuary
Holy place, usually the worship space of a church. Sanctuary may mean the area around the altar, especially in liturgical churches. It may be separated from the rest of the church by an altar rail. It may refer to the entire chancel area, including the choir and/or the space reserved for the clergy. It may also refer to the entire interior of the church where worship takes place.
Sacristy
The room adjoining a church where vestments, altar hangings and linens, sacred vessels, and liturgical books are kept until needed for use in worship. Clergy typically vest in the sacristy.
Vesting Room
A room near the sanctuary of a church where clergy and lay people vest. Ordained and lay ministers use this room to put on and take off vestments that are worn in the liturgy. Vestments are usually kept in this room, along with liturgical books and vessels, altar furnishings, and other items needed throughout the year for the worship of the church. This room may also be known as the sacristy or the vestry.