Identify the smallest building block of react.js

In React.js, creating reusable and modular components is at the heart of building dynamic and interactive user interfaces. In React.js, the smallest building block is a component. Components are self-contained, reusable pieces of code that encapsulate a specific piece of functionality or user interface element. They serve as the foundation for building React applications, allowing developers to create modular and maintainable code. Here's a simple example to illustrate the concept: