Places

• Sector, Devon, a location in the county of Devon in south-western England
• Sector, West Virginia
  Sector, West Virginia
  Sector is an unincorporated community in Hampshire County in the U.S. state of West Virginia. It is located along the west bank of the South Branch Potomac River on Fleming-Sector Road across from Glebe....
  
  , an unincorporated community in Hampshire County, West Virginia, United States of America

In computing

• Cylinder-head-sector
  Cylinder-head-sector
  Cylinder-head-sector, also known as CHS, was an early method for giving addresses to each physical block of data on a hard disk drive. In the case of floppy drives, for which the same exact diskette medium can be truly low-level formatted to different capacities, this is still true.Though CHS...
  
   (or "CHS"), an early method for giving addresses to each physical block of data on a hard drive
• Disk sector
  Disk sector
  In computer disk storage, a sector is a subdivision of a track on a magnetic disk or optical disc. Each sector stores a fixed amount of user data. Traditional formatting of these storage media provides space for 512 bytes or 2048 bytes of user-accessible data per sector...
  
  , a physical subdivision of space on a computer disk-storage medium, specifically a subdivision of a "track"
• in portal rendering
  Portal rendering
  In computer-generated imagery and real-time 3D computer graphics, portal rendering is an algorithm for visibility determination. For example, consider a 3D computer game environment, which may contain many polygons, only a few of which may be visible on screen at a given time...
  
  , a convex polygonal segment of map-space used to facilitate calculation of the visibility of objects in a computer display

Geometry

• Circular sector
  Circular sector
  A circular sector or circle sector, is the portion of a disk enclosed by two radii and an arc, where the smaller area is known as the minor sector and the larger being the major sector. In the diagram, θ is the central angle in radians, r the radius of the circle, and L is the arc length of the...
  
  , also known as a "pie piece", the portion of a circle enclosed by two radii and an arc
• Spherical sector
  Spherical sector
  In geometry, a spherical sector is a portion of a sphere defined by a conical boundary with apex at the center of the sphere. It can be described as the union of a spherical cap and the cone formed by the center of the sphere and the base of the cap....
  
  , portion of a sphere enclosed by two radii from the center of the sphere.
• Hyperbolic sector, is a region of the Cartesian plane bounded by rays from the origin to two points (a, 1/a) and (b, 1/b) and by the hyperbola xy = 1.

Fictional uses

• Sector (Star Trek)
  Sector (Star Trek)
  In Star Trek, a sector is a cubic region of space, 20 light-years on each edge. In the region of galaxy around earth, which comprises the Star Trek Universe, a sector contains 6-10 star systems. Sectors are primarily used as the smallest volume of space, or basic unit, in galactic mapping...
  
  , a fictional area of space-designation used in the Star Trek universe for interstellar navigation
• Sector General
  Sector General
  Sector General is a series of twelve science fiction books and various short stories by the Northern Irish author James White. The series derives its name from the setting of the majority of the books, the Sector 12 General Hospital, a huge hospital space station located in deep space, designed to...
  
  , a series of books about an interstellar hospital in Space, written by James White

Other uses

• Sector (economic): one of several subdivisions in an economic system (used for analysis and classification)
• Sector (instrument)
  Sector (instrument)
  The sector, also known as a proportional compass or military compass, was a major calculating instrument in use from the end of the sixteenth century until the nineteenth century. It is an instrument consisting of two rulers of equal length which are joined by a hinge. A number of scales are...
  
  , also known as a "proportional compass" or "military compass", a calculating instrument consisting of two rulers (of equal length) joined by a hinge
• Sector lights
  Sector lights
  Sector lights are a man-made pilotage and position fixing aid that consist of strictly de-limited horizontal angle light beams to guide water-borne traffic through a safe channel at night in reasonable visibility. They are most often used for safe passage through shallow or dangerous waters. This...
  
  , one of three areas relative to a shallow-water navigational channel
• United States Coast Guard Sectors
  United States Coast Guard Sectors
  A Sector is a shore-based operational unit of the United States Coast Guard. Each Sector is responsible for the execution of all Coast Guard missions within its Area of Responsibility , with operational support from Coast Guard Cutters and Air Stations. Subordinate commands within a Sector...
  
  , a shore-based operational unit of the United States Coast Guard
• "SECTOR", a United States nationwide radio network operated by the U.S. Immigration and Customs Enforcement
  U.S. Immigration and Customs Enforcement
  U.S. Immigration and Customs Enforcement is a federal law enforcement agency under the United States Department of Homeland Security , responsible for identifying, investigating, and dismantling vulnerabilities regarding the nation's border, economic, transportation, and infrastructure security...