Extension - Definition and Overview

• In metaphysics, extension is the property of taking up space; see Extension (metaphysics).
• In semantics (with applications to both philosophy and mathematics), extension is the set of things to which a property applies; see Extension (semantics).
• In mathematics, an extension of some structure is another structure which contains the original structure.
  • For the extension of a group or algebra, see extension (algebra).
  • For the extension of a field, see field extension.
  • For the extension of a bounded linear operator, see continuous linear extension.
• Extension (geology)
• Extension (telephone)
• In computing:
  • For the programming concept, see extension (computing)
  • For the last part of a filename, see filename extension.
• Agricultural extension is the application of scientific research and new knowledge to agricultural practices through farmer education.
• Electricity: extension cord.
• Electronics: extension cable.