What is Virtual DOM? Difference between virtual DOM and real DOM?

In simple words, virtual DOM is just a copy of the original DOM kept in the memory and synced with the real DOM by libraries such as React DOM. This process is called Reconciliation.
Reconciliation is a process to compare and keep in sync the two files (Real and Virtual DOM). Diffing algorithm is a technique of reconciliation that is used by React.

Real DOM

• DOM is a language-neutral interface allowing programs and scripts to dynamically access and update multiple objects like content, structure, and style of a document.
• The DOM denotes the document as nodes and objects.
• It is an object-oriented representation of a web page, modified with a scripting language like JavaScript.

Virtual DOM

• Is a collection of modules designed to provide a declarative way to represent the DOM for an application.
• A virtual DOM object is a representation of a DOM object, like a lightweight copy.
• Virtual DOM is ideal for mobile-first applications.