Mac Catalyst Split View Controller (UISplitViewController)

A UISplitViewController is a container view controller that displays two side-by-side panes — a primary (sidebar) column and a secondary (detail) column — within a Mac Catalyst application. Developers use it to adapt an iPad-style master-detail interface to the macOS desktop experience, providing a navigation structure that feels native on the Mac. When building a Mac Catalyst app, adopting a split view controller helps meet macOS user expectations for layout and navigation patterns.