a sanctuary
The sanctuary is the elevated space where the ceremonies are led from. The nave is the name of the space people gather in. If there is not archetectural differences, ie the sanctuary is not elevated, then the whole space could be called the sanctuary.
In the Catholic Church, the primary ceremony of the Catholic Mass is celebrated in an open area known as the "sanctuary" with the altar as its focal point. The sanctuary is a place apart, traditionally separated from the rest of the Church by an altar railing, although this boundary is rarely found in modern churches. In modern churches, therefore, the demarcation of the sanctuary is either blurred or indistinguishable, though modern thought perceives this as a positive development as the people should be included in the 'sanctuary' to better participate in the liturgy.
The sanctuary.
The room is called a Sacristy.
This room is called the Vestry or Sacristry.vestry: a room in a church where sacred vessels and vestments are kept or meetings are held.or it is called a sanctuary.
Sacristy
The area where the congregation sits in a church is called the pews.
A clergyman's robing room is typically called a vestry or sacristy. It is a designated space where clergy members can prepare for religious services by donning their ceremonial garments and vestments.
Chapel, church, temple.
That would be Church, and the room we all worship in is called the Sanctuary.
A sacred place to worship God is a church, mosque, temple, shrine, or any other place where religious ceremonies and prayers are conducted as acts of devotion and reverence towards a higher power. These places often hold special significance for religious communities and serve as locations for communal worship and spiritual connection.
The room is called the Confessional.
In the New Testament, 'ekklesia' is the Greek term used for those 'called out' as the new Church. Many met in houses at this time. There are some in Christianity that would point to the 'Upper Room' as the first Church or meeting place of the new following. In the Catholic denomination, this room is called the 'Cenacle' and considered by them to be the first Church in Christendom.
From the way it sounds, it seems you are referring to the Altar.
If there is only one room, then it is just called "the chapel", if it is divided, the sanctuary is where the altar is, and the nave would be outside the sanctuary where there would be pews, etc. If there is an anteroom, it is called a narthex.