Discover the Differences Between HTML, CSS, and Javascript
Learn about the differences between HTML, CSS, and JavaScript—the three core technologies for creating websites - in this comprehensive guide.
If you are interested in web development, you might have heard of HTML, CSS, and JavaScript. These are three of the most popular and essential technologies for creating websites.
However, what are they exactly? How do they differ from each other? In this article, we will explain what HTML, CSS, and JavaScript are and the differences between them. We will also provide some resources for learning these technologies and becoming a web developer.
What Is HTML, CSS, and JavaScript?
Before learning about the differences between HTML, CSS, and JavaScript, you need to know about them first. HTML, CSS, and JavaScript are the building blocks of the web. They are used to create web pages' structure, style, and functionality. Let us look at each of them briefly:
HTML stands for HyperText Markup Language. It is a markup language that defines the content and layout of a web page. HTML uses tags to mark different elements of a web page, such as headings, paragraphs, images, links, and forms. HTML tags are enclosed in angle brackets (< and >) and usually come in pairs, such as <p> and </p>. For example, the following HTML code creates a paragraph with some text:
<p>This is a paragraph written in HTML.</p>
CSS stands for Cascading Style Sheets. It is a style sheet language that describes how HTML elements are displayed on the screen. CSS uses rules to apply different styles to HTML elements, such as colors, fonts, backgrounds, borders, and margins. CSS rules consist of selectors and declarations. Selectors specify which HTML elements to style, while declarations specify the styles to apply. Declarations are enclosed in curly braces ({ and }) and consist of properties and values, separated by a colon (:). For example, the following CSS code changes the color and font size of all paragraphs on a web page:
JavaScript is a scripting language that adds interactivity and dynamic features to web pages. It can manipulate HTML and CSS elements, respond to user events, communicate with web servers, store and retrieve data, and perform complex calculations. JavaScript code can be embedded in HTML tags using <script> and </script> or stored in external files with the .js extension. For example, the following JavaScript code displays an alert message when clicking a button:
<button id="my-button">Click Me</button>
<script>
// Get the button element by its id
var button = document.getElementById("my-button");
// Add a click event listener to the button
button.addEventListener("click", function() {
// Display an alert message when the button is clicked
alert("You clicked the button!");
});
</script>
An analogy between HTML, CSS, and JavaScript
Is HTML and CSS Easier than JavaScript?
HTML and CSS are not programming languages but markup and style sheet languages. They are used to define the structure and appearance of web pages. However, they cannot perform any logic or computation. JavaScript, on the other hand, is a programming language that can execute commands and manipulate data.
Therefore, HTML and CSS are generally easier to learn and use than JavaScript, as they have simpler syntax and rules. However, this does not mean HTML and CSS are less important or influential than JavaScript. In fact, HTML, CSS, and JavaScript are complementary and interdependent technologies that work together to create modern and interactive web pages.
There are many differences between HTML, CSS, and JavaScript. However, here are some of the most notable ones:
Purpose. HTML is responsible for the content and structure of a webpage, while CSS determines its presentation and style. Finally, JavaScript is used to define the behavior and functionality of the webpage.
Syntax. HTML employs tags to identify different elements of a web page. At the same time, CSS leverages rules to apply distinctive styles to those specific elements. JavaScript, on the other hand, employs statements to enable various actions and operations.
File extension. Web pages comprise different types of files, each with its unique extension. HTML files typically end with either .html or .htm. CSS files end with .css. Finally, JavaScript files use the .js extension.
Placement. HTML code can be placed anywhere on a webpage. Meanwhile, CSS code can be placed either in a separate <style> tag, an external file, or the <head> section of the web page. Similarly, JavaScript code can be placed in a separate <script> tag, the <head> or <body> section of the webpage, or an external file.
Interaction. HTML and CSS cannot interact with each other directly. However, they are linked using the class or id attributes of HTML elements and the corresponding selectors of CSS rules. Meanwhile, JavaScript can interact with both HTML and CSS using the Document Object Model (DOM), representing the web page as a tree of objects that JavaScript can access and modify.
Examples of How HTML, CSS, and JavaScript Are Used Together
Despite the differences between HTML, CSS and JavaScript, they are used together to create web features. To demonstrate this, let us create a navigation bar and form validation.
Navigation Bar
A navigation bar is a menu—either horizontal or vertical—that helps users navigate to different parts or pages of a website.
Here, we can use the <nav> tag in HTML to create a navigation bar with a list of links within the <ul> and <li> tags. CSS properties such as display, flex, align-items, and background-color can be used to style the navigation bar. Additionally, JavaScript can add interactivity to the navigation bar with events like click, hover, and toggle.
For instance, the following code creates a basic horizontal navigation bar with three links:
<nav>
<ul>
<li><a href="#">Home</a></li>
<li><a href="#">About</a></li>
<li><a href="#">Contact</a></li>
</ul>
</nav>
<style>
/* Style the navigation bar */
nav {
/* Use flexbox to align the items horizontally */
display: flex;
/* Center the items vertically */
align-items: center;
/* Set the background color */
background-color: lightblue;
}
/* Style the list of links */
ul {
/* Remove the default list style */
list-style: none;
/* Use flexbox to align the items horizontally */
display: flex;
/* Add some margin and padding */
margin: 0;
padding: 0;
}
/* Style the list items */
li {
/* Add some margin and padding */
margin: 10px;
padding: 10px;
}
/* Style the links */
a {
/* Remove the default link style */
text-decoration: none;
/* Set the font color */
color: black;
}
/* Change the link color when hovered */
a:hover {
color: white;
}
</style>
<script>
// Get the list of links by their tag name
var links = document.getElementsByTagName("a");
// Loop through the links
for (var i = 0; i < links.length; i++) {
// Add a click event listener to each link
links[i].addEventListener("click", function(event) {
// Prevent the default link behavior
event.preventDefault();
// Display an alert message with the link text
alert("You clicked on " + this.textContent + "!");
});
}
</script>
Form Validation
Form validation is a crucial process that checks the user input on a web form and prompts an error message if the information entered is invalid.
To create a form validation, HTML provides the <form> tag, which includes different input elements like <input>, <select>, and <textarea>. Aesthetic and organized form design can be achieved using CSS properties such as display, width, height, border, and color.
Finally, we will use JavaScript to utilize events such as submit, change, and blur to make the form validation more interactive and efficient.
Take, for instance, the following code, which creates a simple form validation that verifies if the user has inputted a valid email address:
<form id="my-form">
<label for="email">Email:</label>
<input type="email" id="email" name="email" placeholder="Enter your email">
<span id="error" style="display: none; color: red;">Invalid email address.</span>
<button type="submit">Submit</button>
</form>
<style>
/* Style the form */
#my-form {
/* Set the width and height */
width: 400px;
height: 100px;
/* Add some margin and padding */
margin: 20px;
padding: 10px;
/* Set the border style */
border: 2px solid black;
}
/* Style the label */
label {
/* Set the font size and weight */
font-size: 18px;
font-weight: bold;
/* Add some margin and padding */
margin: 10px;
padding: 5px;
}
/* Style the input */
input {
/* Set the width and height */
width: 200px;
height: 20px;
/* Add some margin and padding */
margin: 10px;
padding: 5px;
/* Set the border style */
border: 1px solid gray;
}
/* Style the button */
button {
/* Set the width and height */
width: 100px;
height: 30px;
/* Add some margin and padding */
margin: 10px;
padding: 5px;
/* Set the background and font color */
background-color: lightblue;
color: black;
}
/* Change the button color when hovered */
button:hover {
background-color: blue;
color: white;
}
</style>
<script>
// Get the form element by its id
var form = document.getElementById("my-form");
// Get the email input element by its id
var email = document.getElementById("email");
// Get the error span element by its id
var error = document.getElementById("error");
// Add a submit event listener to the form
form.addEventListener("submit", function(event) {
// Prevent the default form behavior
event.preventDefault();
// Get the email value
var emailValue = email.value;
// Check if the email value is a valid email address
if (validateEmail(emailValue)) {
// If valid, display a success message
alert("Your email is valid!");
} else {
// If invalid, display an error message
error.style.display = "inline";
}
});
// Add a change event listener to the email input
email.addEventListener("change", function() {
// Hide the error message
error.style.display = "none";
});
// A function that validates an email address
function validateEmail(email) {
// Use a regular expression to test the email format
var regex = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
return regex.test(email);
}
</script>
Resources for Learning HTML, CSS, and JavaScript
If you want to learn more about HTML, CSS, and JavaScript, there are many online resources available. Here are some of the most popular and valuable ones:
W3Schools is a highly visited and trusted website that offers tutorials, references, and examples for HTML, CSS, JavaScript, and other web technologies. With a wealth of information at your fingertips, W3Schools is the go-to resource for anyone looking to expand their knowledge of web development.
MDN Web Docs is a website that provides ample documentation, insightful guides, and plentiful resources on various web technologies, including HTML, CSS, and JavaScript. Mozilla, the developers behind the Firefox web browser, along with other web community members, contribute to its maintenance.
Codecademy is a widely popular website that offers interactive courses and exercises for popular languages such as HTML, CSS, and JavaScript. It ranks high among user-friendly platforms to learn coding from.
freeCodeCamp is another excellent resource. This non-profit organization provides self-paced courses and projects for HTML, CSS, JavaScript, and other web technologies. Its ultimate goal is to assist individuals in acquiring coding skills and securing a job as a web developer.
Coursera is an online learning platform that offers courses and certificates in various web technologies like HTML, CSS, and JavaScript. It collaborates with top universities and organizations to provide high-quality and affordable education.
Conclusion
HTML, CSS, and JavaScript are the three core technologies for creating websites. They have different purposes, syntaxes, and features. However, they work together to create the web pages we see and use daily.
Learning HTML, CSS, and JavaScript is a great way to start your journey as a web developer and create your web projects. We hope this article has helped you understand the difference between HTML, CSS, and JavaScript and inspired you to learn more about them. Happy coding!
