Introduction to Lists in React Native

1,000 contacts given to a ScrollView create 1,000 rows on the first render. The same 1,000 contacts given to a FlatList create 10. Both components can show a long scrolling list, but that difference decides which one suits your data.

ScrollView, 1,000 contacts:  1000 rows mounted, Contact 1000 exists
FlatList, 1,000 contacts:      10 rows mounted, Contact 11 does not exist yet

Almost every app shows a list of some kind, such as contacts, products, messages, or a news feed. The data usually comes from an API, a database or user input, so you cannot write each row by hand