How React Components Work as a Templating Engine for Reusable UI

React components function similarly to traditional templating engines by allowing developers to break HTML into reusable, data-driven building blocks. A component is essentially a JavaScript function that returns JSX, a syntax that resembles HTML but compiles into JavaScript objects under the hood. Components must be named with a capital letter and can accept external data through props, which are passed from parent to child but cannot be directly modified by the child. React also enforces a single root element per component, with empty fragment tags serving as lightweight wrappers to avoid unnecessary DOM nodes. This tutorial walks through creating a comment section by composing multiple smaller components, such as Avatar, CommentHeader, and CommentActions, into a parent Comment component.