3.5 presentation of modules

Now that we have a high-level overview of React and of why we might want to use it, this section is going to dive into every basic concept you need to build any kind of React application. We are going to explore the fundamental features and, above all, learn how to design user interfaces around the idea of components — the concept React is built upon.

Of course I will also explain what components actually are, and why React makes them so central. Specifically, in this section we will cover the basic syntax, a special syntax called JSX (what it is and why we use it), how to build our own components and how to make them work together. We will also learn how to deal with data inside a React application, because most real-world apps do more than show static text — they generate, update and react to changing data on the screen.

What you will learn in this module

• The basic syntax of React and what components are.
• JSX — what it looks like and why we use it.
• How to create and use your own custom components.
• How to pass data between components and update what is displayed.

I do not want to teach all of this through theory or boring slides only. We will have just enough theory, and we will mostly learn by building a small example project: an expense tracker, written entirely with React. We will keep using this same application across the upcoming sections because React has many fundamental features, and we will gradually need most of them. It may look trivial at first, but by the time we finish this first app you will have learned almost every key concept you need to build any other React application after that. Let's dive in.

Summary

This lesson introduces the fundamental modules and building blocks of React, focusing on component-based architecture and JSX syntax. You'll learn how to create custom components, manage data dynamically, and build practical applications using React's core features. The section is supported by a hands-on expense tracking application example that demonstrates all key concepts step-by-step.

Key points

• React is built on a component-based architecture—learn why components are central to building user interfaces
• JSX is a special syntax extension that simplifies writing React code and makes components more readable
• Custom components can be created and reused throughout your application to structure code efficiently
• Data management in React allows you to update and display dynamic information as the app changes
• Foundational concepts taught through practical, real-world projects like an expense tracker application
• Understanding these base features prepares you for all advanced React patterns in future lessons

FAQ

What are modules in React and why are they important?

Modules in React refer to reusable components—self-contained pieces of UI logic and structure. They're important because they allow you to build complex interfaces by composing smaller, manageable pieces rather than writing monolithic code, making applications more maintainable and scalable.

What is JSX and how does it make React development easier?

JSX is a special syntax extension that lets you write HTML-like code inside JavaScript. It simplifies component creation by allowing you to define structure, styling, and logic together in a readable way, rather than using complex function calls to build the DOM.

Will I learn to build a real application in this section?

Yes. This section teaches concepts through a hands-on expense tracking application built step-by-step. By completing this project, you'll have learned all the essential React concepts you need to build real-world applications.