Flutter commonly uses keys when it needs to uniquely identify specific widgets within a collection . Using keys also helps Flutter preserve the state of StatefulWidget s while they’re being replaced with other widgets or just moved in the widget tree.
Read moreWhy do we need widgets in Flutter?
Flutter widgets are built using a modern framework that takes inspiration from React. The central idea is that you build your UI out of widgets. Widgets describe what their view should look like given their current configuration and state .
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