The term hemisphere is used in three different meanings:

• one-half of the Earth (or other planetary or stellar body; see also New World and Old World)
  • Eastern Hemisphere and Western Hemisphere.
  • Northern Hemisphere and Southern Hemisphere.
  • A land hemisphere and a water hemisphere.
• one-half of any spherical object, divided at a great circle.
• one of the two principal parts of the brain, each roughly hemispherical: the left or right cerebral hemispheres
• Hemispheres (album), any of three musical albums.