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# The Three Pillars of Web Programming

A webpage is the result of **HTML, CSS, and JavaScript** working together seamlessly.

By effectively utilizing these three elements, you can create not only simple websites but also complex, interactive applications, including web-based games and dynamic user interfaces.

What roles do HTML, CSS, and JavaScript play in web development?

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## HTML: The Skeleton of a Webpage

HTML is like the `skeleton` of a person.

It defines the structure of a webpage and organizes the **content** that appears on the screen.

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## CSS: The Clothes of a Webpage

CSS is like the `clothes` of a person.

Using CSS, you can apply **design** elements like style, color, and size to HTML elements.

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## JavaScript: The Brain of a Webpage

JavaScript is like the `brain` of a person.

Used alongside HTML and CSS, JavaScript adds interactivity and **dynamic functionality** to a webpage.

Dynamic functionality refers to actions such as changing the background color when a specific button is clicked or validating the value entered in an input field (e.g., ensuring a password is at least 6 characters long).

### Experience Coding with JavaScript

In programming, a `variable` is a **space in memory** where you can store a value. Simply put, a variable is a box that temporarily holds data.

Using JavaScript, you can declare a variable to process data and recall the stored value whenever needed.

`let` is a reserved word in JavaScript used to create a box that can hold data, the value of which can be changed at any time.

The JavaScript code `let myCurrentIndex = 490` stores the value `490` in a variable named `myCurrentIndex`. If you change 490 to any other number between 0 and 783, you can observe a change in the initial position of the character.

Enter `let` in the blank below to complete the JavaScript code that declares a variable.