The Apple Keyboard II was first released in 1990 with the Macintosh Classic and LC. This keyboard included flip-down feet in the back to increase the angle of the keyboard for more comfortable typing. This keyboard used the ADB (Apple Desktop Bus) connector.
While this keyboard used the same color of Platinum gray as Macintosh computers at the time, it was also included with the Macintosh TV in all black (using the same model number).
As of 2020 Apple has released approximately 20 external keyboard designs. In general, Apple Macintosh keyboards are different from standard keyboards because they include a Command key (⌘) for shortcuts; an Option key (⌥) for entering diacritical marks and special characters; and a Help or fn (function) key. Earlier Apple keyboards also included a power key (◁), while newer keyboards include eject (⏏).
Source: Wikipedia