How is the unification of behavior elements of UICollectionView and UITableView implemented in iOS?

Unification of the behavior of UICollectionView and UITableView in iOS is achieved through the use of common protocols and architectural patterns.

Both collections use delegate and data source protocols, which define methods for managing display and interaction with items.

Additionally, starting from iOS 14, Apple introduced UICollectionView with list support, which is very similar in functionality and API to UITableView. This allows using similar approaches for working with data and cells.

Furthermore, abstractions and wrappers are often used to hide differences between these components, enabling work through a unified interface. For example, creating a protocol that describes basic operations with list items and implementing it for both collections.