What is Virtual DOM?
It is a lightweight, JavaScript representation of the actual DOM. It lives in the memory and acts as a middle layer between the code and the browser's UI.
The Problem it Solves:
Manipulating the Real DOM is slow and expensive. Whenever a small change occurs, the browser often re-calculates the layout and styles for the entire page, which kills performance.
How it works:
• Step 1: When data changes, a new Virtual DOM tree is created.
• Step 2 (Diffing): This new tree is compared with the previous version to find exactly what changed.
• Step 3 (Reconciliation): Only the specific changes are pushed to the Real DOM, instead of re-rendering everything.
Scenario:
Updating a single "Like" count on a post. Instead of refreshing the whole post and its comments, the Virtual DOM identifies only the number changed and updates just that specific node.
May 14, 2026 192
