What does 20-key keyboard mean?

20-key keyboard meaning in Computer Science Dictionary

The 20-key keyboard, in addition occasionally known as half-QWERTY, is made similarly to the typical QWERTY keyboard used with computers. Most of the secrets consist of two letters on each of those, as well as either lots or image (exclamation point, question mark at (@) logo). Various other functions included are Caps Lock, Shift, Spacebar, Backspace, and get back key.