React's Herrustic Algorithm

React's reconciliation is done by comparing the types of the nodes within the trees. So if the node in the same place in two trees are of the same type, then React knows it doesn't need to create a new DOM element and add it to the screen. The first node in the output for the list needs to have the special property set called key. In normal React programming, that is really the only extra thing you need to care about.