(1) (Qi) See
Qi wireless charging.
(2) A keyboard button. See
QWERTY keyboard.
(3) A numeric code that is used with an encryption algorithm to encrypt text for security purposes. See
key length,
key space,
cryptography and
salt.
(4) An essential field in a database record. See
key field and
sort key.
(5) Amazon's door entry system for package delivery. See
Amazon Key.
(6) A physical generation identification. See
keyed.