How to Configure Scroll Bars in OS X and macOS
Set up your scroll bars to meet your own personal preferences.
Control Your Scrolling Speed
Apple also makes it easy to adjust the scrolling speed of your mouse or trackpad.
Automatically based on mouse or trackpad: Scroll bars appear only when the cursor is in the scroll bar area or when you start scrolling.When Scrolling: Scroll bars show up only when you start scrolling on your mouse or trackpad.Always: Scroll bars are always visible.
Jump to the next page: Clicking in the scroll bar moves to the next or previous page of the document or page you’re on, depending on whether you click below or above the scroll box.Jump to the spot that’s clicked: The scroll box will move to wherever your cursor is.
In macOS Catalina
The interface is a little different with Catalina than earlier macOS and OS X versions.