What phrase applies both to the presiding officer and to the position where he/she presides?

The phrase that applies to both the presiding officer and the position where he or she presides is "the chair." In parliamentary procedure, the term "chair" is commonly used to refer to the individual who leads a meeting or assembly, as well as to the role itself or the office they occupy. For example, one might say, "The chair will now entertain a motion," as well as refer to a specific position within an organization as "the chair." This term encompasses both the person and the role effectively, demonstrating its dual applicability.

Other options do not convey this dual meaning as succinctly. While "the leader" and "the head" describe the authority or guidance role of the presiding officer, they do not specifically denote the position itself or its functions within formal parliamentary procedures. The term "the moderator," on the other hand, can describe someone who oversees discussions but does not specifically reflect the presiding officer's formal role in assembly procedures, where "chair" is the standardized terminology used for this purpose.