Key

Key may refer to:

Devices

• Key (lock), a device used to open a lock
• Churchkey, various kinds of bottle and can openers
• Keychain, small chain that connects a small item to a keyring

Music

• Key (instrument), musical intruments have keys for tuning and keys for playing
• Key (music), a set of notes
• Key signature, in musical notation

Programming

• Key, button on a computer keyboard
• Candidate key, set of attributes of a relation variable in the relational model
• Foreign key, field or group of fields in a database record that point to a key field or group of fields forming a key of another database record
• Key, the index into a hash table
• Key (cryptography), a piece of information that controls the operation of a cryptography algorithm
• Keying (graphics), compositing two full frame images together
• Keyword (computer programming), word or identifier that has a particular meaning to a programming language
• Keyword (internet search), one of the words used to find matching pages
• Keyword stuffing, unethical search engine optimization technique
• USB key, a computer storage device

Geography

• Florida Keys
• Key, a small, low island

Artistry

• Black, in the CMYK color model
• Key frame, a frame made by an animator from which other frames are derived
• Key plate, a plate which printed the detail in an image

Fiction

• Key (comics), a DC Comics supervillain
• Keyblade, the main weapon of the main character of the Kingdom Hearts series

Literature

• Key (company), a Japanese visual novel studio
• Keyword (linguistics), word which occurs in a text more often than we would expect to occur by chance alone
• Keywords: A Vocabulary of Culture and Society, book written by the Welsh Marxist academic Raymond Williams
• The Keys to the Kingdom, a fantasy-adventure book series

Surname

For people named Key, see Key (surname).

Other

• House of Keys, the lower branch of the Isle of Man's Parliament
• Identification key, a method of deducing the correct species assignment of a living thing
• Key Bank, a bank
• Key Club, a worldwide student service organization
• Keying (vandalism), paint scratching
• Telegraph key, the button used by a telegraph operator

See also

• Quay
• Key: Defined, A crucial step or requirement