What is the difference between virtual DOM and regular DOM?

The Virtual DOM is a lightweight copy of the real DOM that exists in memory and is used to optimize interface updates. Unlike the regular DOM, which is a structure of elements in the browser and directly affects rendering, the virtual DOM allows changes to be made first to the virtual structure, and then efficiently updates the real DOM, minimizing the number of operations and re-renderings.

Main differences:

• Performance: Changes are first applied to the virtual DOM, then the minimal set of changes is calculated for the real DOM.
• Abstraction: The virtual DOM is an object model in memory, while the regular DOM is a browser API.
• Updates: The virtual DOM allows for diffing (comparing old and new states) to optimize updates.

Example: React uses the virtual DOM for efficient component rendering.