A dual layout keyboard is one that is compatible across different operating systems (OS) such as macOS, Windows, iOS, Chrome, Android, and so on.

Some keys on a dual layout keyboard can perform actions on different operating systems while they maintain their original position. When a key is capable of performing different functions on different operating systems, the functions and operating system are indicated by label colors and split lines.

What are modifier keys, and what do they do?

Modifier keys are special keys on your keyboard that temporarily modify the normal action of another key when pressed together. By themselves, modifier keys usually do nothing; that is, pressing any of the ⇧ Shift, Alt, or Ctrl keys alone does not generally trigger any action from the computer.

Modifier keys on dual layout keyboards

While the Windows layout has an Alt key on either side of the space bar, macOS has a CMD key in the same positions.On a dual layout keyboard, the keys next to the space bar can do both the Alt and CMD actions, depending on what OS the keyboard is connected to.The label on these keys mention both OS-specific functions they can perform, separated by a line.

For Windows, Android and Linux users: 

The special characters are on the right side of the keys:

For macOS, iOS or iPadOS users:

The special characters are on the left side of the keys: