HTML & CSS: The Building Blocks of the Web
HTML (HyperText Markup Language)
What it is: HTML is the standard markup language used to create and structure content on the web.
Key characteristics:
- Provides the skeleton/structure of a webpage
- Uses tags (like
<html>
,<head>
,<body>
,<p>
,<div>
) to define elements - Not a programming language - it's a markup language
- Current version is HTML5
Basic HTML document structure:
<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
</head>
<body>
<h1>My First Heading</h1>
<p>My first paragraph.</p>
</body>
</html>
CSS (Cascading Style Sheets)
What it is: CSS is the language used to style and layout web pages.
Key characteristics:
- Controls presentation, formatting, and appearance
- Works with HTML to make pages visually appealing
- Uses selectors to target HTML elements
- Current version is CSS3
Basic CSS example:
body {
background-color: lightblue;
}
h1 {
color: white;
text-align: center;
}
p {
font-family: verdana;
font-size: 20px;
}
How They Work Together
- HTML defines the content and structure ("This is a heading, this is a paragraph")
- CSS defines the presentation ("The heading should be red and centered, paragraphs should use Arial font")
Methods of applying CSS:
- Inline (using the
style
attribute in HTML elements) - Internal (using
<style>
tags in the HTML<head>
) - External (linking to a separate
.css
file - most recommended method)
Key Concepts
HTML:
- Semantic elements (
<header>
,<footer>
,<article>
) - Forms and inputs
- Links and navigation
- Images and multimedia
CSS:
- Selectors (element, class, ID)
- Box model (margin, border, padding, content)
- Positioning (static, relative, absolute, fixed)
- Flexbox and Grid layout systems
- Responsive design (media queries)
Together, HTML and CSS form the foundation of nearly every website on the internet.
At Online Learner, we're on a mission to ignite a passion for learning and empower individuals to reach their full potential. Founded by a team of dedicated educators and industry experts, our platform is designed to provide accessible and engaging educational resources for learners of all ages and backgrounds.
Terms Disclaimer About Us Contact Us
Copyright 2023-2025 © All rights reserved.