Chancel
[chan-suhl, chahn-]
Etymology: Middle English, from Anglo-French, from Late Latin cancellus lattice, from Latin cancelli; from the latticework enclosing it

Chancel: The eastern end of a church

Choir (Quire)
(kwir)
Etymology: Middle English quer, from Anglo-French queor, from Medieval Latin chorus, from Latin, chorus

Choir: The area of the church between a transept and main apse. It is the area where the service is sung and clergy may stand, and the main or high altar is located.

*term definitions retrieved from pitt.edu and britainexpress.com

*image retrieved from Encyclopedia Britannica Online (eb.com)