A section. (Can we add an example for this sense?)

A noun "sector" represents a zone or designated area, typically used in military contexts to refer to a specific operational or responsibility area, or in science fiction to describe a fictional region of space for navigational or governance purposes.

(geometry) Part of a circle, extending to the center; circular sector.

(computer hardware) A fixed-sized unit (traditionally 512 bytes) of sequential data stored on a track of a digital medium.

(calculation) An instrument consisting of two rulers of equal length joined by a hinge.

A field of economic activity.

(engineering) A toothed gear whose face is the arc of a circle.

(motor racing) A fixed, continuous section of the track, such that sectors do not overlap but all sectors make up the whole track.

(climbing) An area of a crag, consisting of various routes