It also refers to a relational database table, a column, or a set of columns whose values identify one or more rows.
With a computer keyboard, a key is one of the keyboard’s buttons. Letters, numbers, functions, and symbols are all represented on keys.
When a keyboard key is pressed down, that key is sent as input to the computer and appears on the screen. Clicking the following box with your mouse and then typing any letter key on the keyboard makes it appear in the box.
Example of usage – “When there was news of a data breach in their partner organization, the manager decided to change the cryptographic key in order to better protect the confidential data.”