A feature of church architecture, this is the area surrounding the altar that is separated from the congregation by an altar rail and by the rood screen. Properly speaking, the area within the altar rail, immediately surrounding the altar, is the sanctuary, and the chancel includes the area in which clergy, acolytes (and in some churches the choir) sit during worship, as separated from the main congregational area (the nave) by an aisle, space, or a rood screen.
This architectural feature arose at a time (as was required by a Church council of 1215) during which the people only received Holy Eucharist/Communion very infrequently (perhaps once a year), and the Blessèd Sacrament was thought to require protection/segregation from the crowd. This led to the serious abuse of treating the Blessèd Sacrament as somehow “magical” and “above” most people most of the time. However, the architectural feature has the positive effect of reinforcing to people that they are within a holy place, in God’s presence, and has been maintained in many churches for this reason and for the details of architectural beauty that are made possible by this building design.
The word is originally descriptive; it refers to the place where prayers are chanted.