Editing Scroll wheel (section)

===Scrolling===
Rotating the wheel sends vertical scroll commands in many graphical desktop systems. In many systems, the panel or control under the cursor is scrolled; in [[Microsoft Windows]], however, it's far more common for the scroll events to be sent to whichever control has the focus. This behaviour can be modified through many programs.

Most wheels have tactile detents (notches), each corresponding to a scrolling step. There are typically 24 detents per revolution, but some wheels have only 18.
When a electromechanical [[rotary encoder]] is used, the detents tend to be a property of it. When an optoelectric encoder is used instead, the detents are created by a separate spring.

In Microsoft Windows, each step is a fixed amount of three lines of text.
Faster rotation of the wheel in some systems, including in Apple's [[macOS]], increases the scroll distance per step to provide accelerated scrolling.
Scrolling acceleration is also provided as a feature in the Microsoft IntelliPoint driver software supplied with the IntelliMouse.