Choir or transept.
The part of the cathedral that includes the altar and choir is typically known as the chancel. This area is situated at the eastern end of the cathedral and is often elevated, emphasizing its sacred function. The chancel serves as a space for worship, where the clergy perform rituals and the choir participates in liturgical music. It is distinct from the nave, which is the main body of the church meant for the congregation.
king john
chevet
An antependium is a screen in front of an altar, or an altar cloth.
The nave is the known as the main body in church architecture. From the front door, the first area is a lobby. The larger area inside the church is the nave. The altar is at the front. The pianist or organist and choir may be at the front to the side or rear of the altar, or in the back in a balcony area.
In front!!
It is the front surface the altar.
at the front of the church normally in front of an cross
It's at the front.
The word cathedral can be used as a noun = The cathedral is immense. or as an adjective: The new house has cathedral ceilings.
The word altar is a noun. The plural form is altars.
The opposite of an altar might be a sacrificial table. Also, the altar is in the eastern portion of the church. The portion in the western part opposite to the altar in a church is called the entryway or vestibule.