Key might refer to:

Common meanings

  • Cay, additionally spelled key, a small, low-elevation, sandy island formed on the surface of a coral reef
  • Key (cryptography), a piece of information that controls the operation of a cryptography algorithm
  • Key (engineering), a type of coupling used to transmit rotation between a shaft and an attached item
  • Key (lock), device used to open a lock such as in a door
  • Key (map), a guide to a map's symbology
  • Key, a guide to colours and symbols used in a data chart, graph, plot or diagram


In the United States



Art, entertainment, and media

Fictional characters

Fictional works



Other uses

Visual arts

  • Chroma key, a method to superimpose several video layers using areas of a defined colour as a mask .
  • Key frame, a frame made by an animator from which additional frames are derived
  • Key light, the primary light source that illuminates an image or scene
  • Key plate, a plate which prints the detail in an image, often using the colour black
  • Key colour (typically black), in the CMYK colour model
  • The primary tone of an image, as in:


  • Samara (fruit) or key, a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall, often called "helicopters"
  • Identification key, a method of deducing the correct species assignment of a living thing
  • Single-access key, a method used for categorising species using logical choices

Companies and organizations

  • Keys, a China-based global booking platform for B&B, boutique hotels and luxury apartment.
  • Key (company), a Japanese visual novel studio
  • House of Keys, the directly elected lower branch of Tynwald, the parliament of the Isle of Man
  • Key Club, a worldwide student service organization
  • KeyBank, a bank headquartered in the Key Tower in Cleveland, Ohio




Other uses