It uses a "Virtual DOM" such that it can calculate the most efficient way to modify the real DOM (which is generally very slow). For example, if you change the

It uses a "Virtual DOM" such that it can calculate the most efficient way to modify the real DOM (which is generally very slow). For example, if you change the data model behind an ng-repeat right now, Angular deletes the old element from the DOM and writes a new one. Angular 2, and React, will figure out that just the internal information of the element changed and it will just change that bit.