UIKit.UICollectionViews allow content to be displayed using arbitrary layouts. The UIKit.UICollectionViewFlowLayout provides an easy-to-use flow-based layout.

The UIKit.UICollectionViewFlowLayout lays out UIKit.UICollectionViewCells side-by-side, either horizontally or vertically. Component UIKit.UICollectionViewCells wrap at the boundaries. Cells are spaced in the direction of layout according to the UICollectionViewFlowLayout.MinimumInteritemSpacing property and rows (whether horizontal or vertical) are separated based on the UICollectionViewFlowLayout.MinimumLineSpacing property.

The application developer can use various methods of UIKit.UICollectionViewDelegateFlowLayout to modify the exact spacing and size of cells within a UIKit.UICollectionViewFlowLayout.

The direction of the flow layout is at right angles to the direction of the UICollectionViewFlowLayout.ScrollDirection property. In the following image, the flow layout is left-to-right and the UICollectionViewFlowLayout.ScrollDirection is UICollectionViewScrollDirection.Vertical.