The RMB key on a keyboard stands for Right Mouse Button. It is a button on many keyboards that allows you to perform a right-click action without needing your mouse. The RMB key is usually located at the bottom right of the keyboard, below the Shift key. In computer applications, RMB is used as an abbreviation for right-mouse button. It is often used in combination with other keys to perform various actions, such as displaying manipulators or adjusting the size of manipulators. In 3D applications, RMB is used for camera navigation in 3D environments.