A keyed node helps optimize cases where children are getting added, moved, removed, etc. Common examples include:
When you use a keyed node, every child is paired with a string identifier. This makes it possible for the underlying diffing algorithm to reuse nodes more efficiently.
Works just like
Html.node, but you add a unique identifier to each child node. You want this when you have a list of nodes that is changing: adding nodes, removing nodes, etc. In these cases, the unique identifiers help make the DOM modifications more efficient.