Swift version: 5.0
Index paths describe an item’s position inside a table view or collection view, storing both its section and its position inside that section. For example, the first row in a table would have section 0, row 0, whereas the eighth row in the fourth section would have section 3, row 7.
You’ll be given index paths fairly frequently by iOS, for example when the user tapped on a row, or when UIKit needs to know whether a certain item can be edited.
When working with collection views, you should use the item number of an index path rather than its row number, because row numbers mean different things when multiple items can share the same row.
Available from iOS 6.0
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.