The most basic component of a collection view's layout.
- iOS 13.0+
- macOS 10.15+
- Mac Catalyst 13.0+
- tvOS 13.0+
An item is a blueprint for how to size, space, and arrange an individual piece of content in your collection view. An item represents a single view that's rendered onscreen. Generally, an item is a cell, but items can be supplementary views like headers, footers, and other decorations.
For example, in the Photos app, an item might represent a single photo. In the App Store app, an item might be a cell displaying information about an individual app in a list of featured apps, such as the app icon, app name, tagline, and download button.
Each item specifies its own size in terms of a width dimension and a height dimension. Items can express their dimensions relative to their container, as an absolute value, or as an estimated value that might change at runtime, like in response to a change in system font size. For more information, see
You combine items into groups that determine how those items are arranged in relation to each other. For more information, see