1. What is a Diffing Algorithm?

The Diffing Algorithm is a process React uses to compare the previous UI tree with the new UI tree and identify what has changed.

React uses this comparison to help update the UI efficiently instead of recreating the entire DOM every time.

1. State changes

Example: count changes from 0 to 1

1. React renders again

Creates a new UI description

1. Diffing

Compares the previous and new descriptions

1. DOM update

Applies the necessary changes

1. Important concepts:

• Virtual DOM:
  A lightweight representation of the UI that React uses during rendering.

• Diffing:
  The comparison of the previous and new rendered trees.

• Reconciliation:
  React's broader process of determining how to update the UI; diffing is part of this process.

React also uses element types and key props to determine whether elements can be reused or need to be replaced.