React Virtual DOM

Virtual dom is a carbon copy of Real Dom which is introduced by React.js to optimize the performance of a web Application.

With the process of “reconciliation”, React kept a virtual representation of the UI in memory and when something changed in UI React compares the change with the virtual representation and commits only the changes in Real DOM.

When anything is updated before updating React takes a copy of the DOM and after updating React compares the pre-update DOM with the post-update and finds out the main changes and only the changes are updated on the screen. This process is called ‘diffing’.