Key

Look up key in Wiktionary, the free dictionary.

Key may refer to:

Common meanings

• Cay, also 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 (electrical), mechanical component in a plug or socket which prevents mating except with a correctly oriented matching connector
• Key (lock), a device used to open a lock such as in a door, safe, or other openings to objects or places.
• Key (map), a guide to a map's symbology

Places

People

• Key (singer) (born 1991), a South Korean entertainer

Art, entertainment, and media

Music

Visual arts

• Chroma key, a method to superimpose several video layers using areas of a defined color as a mask
• Key frame, a frame made by an animator from which other 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 color black
• Key color (typically black), in the CMYK color model
• The primary tone of an image, as in:
  • high key images
  • low key images

Biology

• 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 categorizing species using logical choices

Companies and organizations

• 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

Databases

• Superkey, a set of attributes of a relation variable for which it holds that in all relations assigned to that variable
  • Compound key, a set of superkeys that is not minimal
  • Unique key, a superkey in database relational modeling and implementation where there are no two distinct tuples (rows) that have the same values
    • Natural key, a type of unique key found in relational model database design that is formed of attributes that already exist in the real world
• Primary key, a set of attributes (columns) that uniquely specify a tuple (row) in a relation (table)
  • Foreign key, a field or collection of fields in one table that uniquely identifies a row of another table or the same table
• Surrogate key, a unique identifier for either an entity in the modeled world or an object in the database

Computing

• Computer keyboard keys
• KeY, a software verification tool
• .key, file extension used by Keynote (presentation software)
• Key, attribute, or property, a data element which allows one to find associated data value or values by using a database index, hash table or a Memory location; see attribute-value pair.

Education

• Key English Test, an international examination of basic level of English language.
• Answer key, list of answers to a test (assessment)

Sports

• Key (basketball), a restricted area around the basketball net
• Frederick Keys, a Double-A minor league baseball team

Other uses

• Keys, a truce term used in western Scotland
• Telegraph key, the button used by a telegraph operator

See also

• All pages beginning with Key
• All pages with a title containing Key
• Keay
• Keyes (disambiguation)
• Keying (disambiguation)
• The Key (disambiguation)
• The Keys (disambiguation)
• Quay