Welcome to the exciting world of React! In this first module, we're going to dive into some of the foundational concepts that make React such a powerful tool for building web and mobile applications. Whether you're new to programming or an experienced developer looking to expand your toolkit, you're in the right place to start learning about React. 

Prerequisites

To succeed in this course it would be beneficial if you had:

1. a knowledge of javascript (preferably Typescript) knowledge. If there are any particularities of Javascript that might seem strange we will explain them. 
2. a good knowledge of HTML or XML to buold the structure of our pages
3. an introductory knowledge of CSS to make things look prettier

So, all set? Let's get started!

Who is using React?

You are in a good company. React made it to 80% of Fortune 500 companies including the ones below. Also, if you explore job opportunities in your area, we are sure that you will find many React-based ads. For example, in July, in Australia there have been 1,395 companies searching for react developers! 

What is React?

React is a JavaScript library created by Facebook, designed for building user interfaces. It excels in building complex, interactive, and scalable front-end applications. React’s strength lies in its simplicity and flexibility, allowing developers to compose complex UIs from small, isolated pieces of code called components. Say what, what about what? 

👶 Explain like I'm 10:

Imagine you're building a super cool robot out of LEGOs. Each part of the robot — like its head, arms, and legs — is made from different LEGO blocks. ReactJS is kind of like a special set of LEGOs for building websites on the computer!

When people make websites, they use ReactJS to create little parts of the website, like buttons, pictures, or little sections where text goes. These parts are called "components." Just like how you might use the same type of LEGO block to build different parts of your robot, you can use these components over and over again in different parts of a website. This makes it super fun and easy because once you make a good component, you can use it a lot!

And you know how sometimes you change one part of your LEGO robot, like maybe giving it a different hat, and you don't have to rebuild the whole thing? ReactJS does something like that too! When something needs to change on the website, like if someone clicks a button or writes something, ReactJS only updates the small parts that need to change, not the whole website. It’s pretty smart, huh?

So, ReactJS helps people build and change websites in a really cool and efficient way, kind of like being a master builder with LEGOs! What kind of LEGO creation would you build if you could?

In the next chapter we start building React stuff!