Terrarium Project Part 1: Introduction to HTML

mermaid

journey
    title Your HTML Learning Journey
    section Foundation
      Create HTML file: 3: Student
      Add DOCTYPE: 4: Student
      Structure document: 5: Student
    section Content
      Add metadata: 4: Student
      Include images: 5: Student
      Organize layout: 5: Student
    section Semantics
      Use proper tags: 4: Student
      Enhance accessibility: 5: Student
      Build terrarium: 5: Student

Sketchnote by Tomomi Imura

HTML, or HyperText Markup Language, is the foundation of every website you've ever visited. Think of HTML as the skeleton that gives structure to web pages – it defines where content goes, how it's organized, and what each piece represents. While CSS will later "dress up" your HTML with colors and layouts, and JavaScript will bring it to life with interactivity, HTML provides the essential structure that makes everything else possible.

In this lesson, you'll create the HTML structure for a virtual terrarium interface. This hands-on project will teach you fundamental HTML concepts while building something visually engaging. You'll learn how to organize content using semantic elements, work with images, and create the foundation for an interactive web application.

By the end of this lesson, you'll have a working HTML page displaying plant images in organized columns, ready for styling in the next lesson. Don't worry if it looks basic at first – that's exactly what HTML should do before CSS adds the visual polish.

mermaid

mindmap
  root((HTML Fundamentals))
    Structure
      DOCTYPE Declaration
      HTML Element
      Head Section
      Body Content
    Elements
      Tags & Attributes
      Self-closing Tags
      Nested Elements
      Block vs Inline
    Content
      Text Elements
      Images
      Containers (div)
      Lists
    Semantics
      Meaningful Tags
      Accessibility
      Screen Readers
      SEO Benefits
    Best Practices
      Proper Nesting
      Valid Markup
      Descriptive Alt Text
      Organized Structure

Pre-Lecture Quiz

Pre-lecture quiz

📺 Watch and Learn: Check out this helpful video overview

Setting Up Your Project

Before we dive into HTML code, let's set up a proper workspace for your terrarium project. Creating an organized file structure from the beginning is a crucial habit that will serve you well throughout your web development journey.

Task: Create Your Project Structure

You'll create a dedicated folder for your terrarium project and add your first HTML file. Here are two approaches you can use:

Option 1: Using Visual Studio Code

Open Visual Studio Code
Click "File" → "Open Folder" or use Ctrl+K, Ctrl+O (Windows/Linux) or Cmd+K, Cmd+O (Mac)
Create a new folder called terrarium and select it
In the Explorer pane, click the "New File" icon
Name your file index.html

Option 2: Using Terminal Commands

bash

mkdir terrarium
cd terrarium
touch index.html
code index.html

Here's what these commands accomplish:

Creates a new directory called terrarium for your project
Navigates into the terrarium directory
Creates an empty index.html file
Opens the file in Visual Studio Code for editing

💡 Pro Tip: The filename index.html is special in web development. When someone visits a website, browsers automatically look for index.html as the default page to display. This means a URL like https://mysite.com/projects/ will automatically serve the index.html file from the projects folder without needing to specify the filename in the URL.

Understanding HTML Document Structure

Every HTML document follows a specific structure that browsers need to understand and display correctly. Think of this structure like a formal letter – it has required elements in a particular order that help the recipient (in this case, the browser) process the content properly.

mermaid

flowchart TD
    A["<!DOCTYPE html>"] --> B["<html>"]
    B --> C["<head>"]
    C --> D["<title>"]
    C --> E["<meta charset>"]
    C --> F["<meta viewport>"]
    B --> G["<body>"]
    G --> H["<h1> Heading"]
    G --> I["<div> Containers"]
    G --> J[" Images"]
    
    style A fill:#e1f5fe
    style B fill:#f3e5f5
    style C fill:#fff3e0
    style G fill:#e8f5e8

Let's start by adding the essential foundation that every HTML document needs.

The DOCTYPE Declaration and Root Element

The first two lines of any HTML file serve as the document's "introduction" to the browser:

html

<!DOCTYPE html>
<html></html>

Understanding what this code does:

Declares the document type as HTML5 using <!DOCTYPE html>
Creates the root <html> element that will contain all page content
Establishes modern web standards for proper browser rendering
Ensures consistent display across different browsers and devices

💡 VS Code Tip: Hover over any HTML tag in VS Code to see helpful information from MDN Web Docs, including usage examples and browser compatibility details.

📚 Learn More: The DOCTYPE declaration prevents browsers from entering "quirks mode," which was used to support very old websites. Modern web development uses the simple <!DOCTYPE html> declaration to ensure standards-compliant rendering.

🔄 Pedagogical Check-in

Pause and Reflect: Before continuing, make sure you understand:

✅ Why every HTML document needs a DOCTYPE declaration
✅ What the <html> root element contains
✅ How this structure helps browsers render pages correctly

Quick Self-Test: Can you explain in your own words what "standards-compliant rendering" means?

Adding Essential Document Metadata

The <head> section of an HTML document contains crucial information that browsers and search engines need, but that visitors don't see directly on the page. Think of it as the "behind-the-scenes" information that helps your webpage work properly and appear correctly across different devices and platforms.

This metadata tells browsers how to display your page, what character encoding to use, and how to handle different screen sizes – all essential for creating professional, accessible web pages.

Task: Add the Document Head

Insert this <head> section between your opening and closing <html> tags:

html

<head>
	<title>Welcome to my Virtual Terrarium</title>
	<meta charset="utf-8" />
	<meta http-equiv="X-UA-Compatible" content="IE=edge" />
	<meta name="viewport" content="width=device-width, initial-scale=1" />
</head>

Breaking down what each element accomplishes:

Sets the page title that appears in browser tabs and search results
Specifies UTF-8 character encoding for proper text display worldwide
Ensures compatibility with modern versions of Internet Explorer
Configures responsive design by setting the viewport to match device width
Controls initial zoom level to display content at natural size

🤔 Think About This: What would happen if you set a viewport meta tag like this: <meta name="viewport" content="width=600">? This would force the page to always be 600 pixels wide, breaking responsive design! Learn more about proper viewport configuration.

Building the Document Body

The <body> element contains all the visible content of your webpage – everything users will see and interact with. While the <head> section provided instructions to the browser, the <body> section contains the actual content: text, images, buttons, and other elements that create your user interface.

Let's add the body structure and understand how HTML tags work together to create meaningful content.

Understanding HTML Tag Structure

HTML uses paired tags to define elements. Most tags have an opening tag like <p> and a closing tag like </p>, with content in between: <p>Hello, world!</p>. This creates a paragraph element containing the text "Hello, world!".

Task: Add the Body Element

Update your HTML file to include the <body> element:

html

<!DOCTYPE html>
<html>
	<head>
		<title>Welcome to my Virtual Terrarium</title>
		<meta charset="utf-8" />
		<meta http-equiv="X-UA-Compatible" content="IE=edge" />
		<meta name="viewport" content="width=device-width, initial-scale=1" />
	</head>
	<body></body>
</html>

Here's what this complete structure provides:

Establishes the basic HTML5 document framework
Includes essential metadata for proper browser rendering
Creates an empty body ready for your visible content
Follows modern web development best practices

Now you're ready to add the visible elements of your terrarium. We'll use <div> elements as containers to organize different sections of content, and `` elements to display the plant images.

Working with Images and Layout Containers

Images are special in HTML because they use "self-closing" tags. Unlike elements like <p></p> that wrap around content, the `` tag contains all the information it needs within the tag itself using attributes like src for the image file path and alt for accessibility.

Before adding images to your HTML, you'll need to organize your project files properly by creating an images folder and adding the plant graphics.

First, set up your images:

Create a folder called images inside your terrarium project folder
Download the plant images from the solution folder (14 plant images total)
Copy all plant images into your new images folder

Task: Create the Plant Display Layout

Now add the plant images organized in two columns between your <body></body> tags:

html

<div id="page">
	<div id="left-container" class="container">
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
	</div>
	<div id="right-container" class="container">
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
		<div class="plant-holder">
			
		</div>
	</div>
</div>

Step by step, here's what's happening in this code:

Creates a main page container with id="page" to hold all content
Establishes two column containers: left-container and right-container
Organizes 7 plants in the left column and 7 plants in the right column
Wraps each plant image in a plant-holder div for individual positioning
Applies consistent class names for CSS styling in the next lesson
Assigns unique IDs to each plant image for JavaScript interaction later
Includes proper file paths pointing to the images folder

🤔 Consider This: Notice that all images currently have the same alt text "plant". This isn't ideal for accessibility. Screen reader users would hear "plant" repeated 14 times without knowing which specific plant each image shows. Can you think of better, more descriptive alt text for each image?

📝 HTML Element Types: <div> elements are "block-level" and take up full width, while <span> elements are "inline" and only take up necessary width. What do you think would happen if you changed all these <div> tags to <span> tags?

🔄 Pedagogical Check-in

Structure Understanding: Take a moment to review your HTML structure:

✅ Can you identify the main containers in your layout?
✅ Do you understand why each image has a unique ID?
✅ How would you describe the purpose of the plant-holder divs?

Visual Inspection: Open your HTML file in a browser. You should see:

A basic list of plant images
Images organized in two columns
Simple, unstyled layout

Remember: This plain appearance is exactly what HTML should look like before CSS styling!

With this markup added, the plants will appear on screen, though they won't look polished yet – that's what CSS is for in the next lesson! For now, you have a solid HTML foundation that properly organizes your content and follows accessibility best practices.

Using Semantic HTML for Accessibility

Semantic HTML means choosing HTML elements based on their meaning and purpose, not just their appearance. When you use semantic markup, you're communicating the structure and meaning of your content to browsers, search engines, and assistive technologies like screen readers.

mermaid

flowchart TD
    A[Need to add content?] --> B{What type?}
    B -->|Main heading| C["<h1>"]
    B -->|Subheading| D["<h2>, <h3>, etc."]
    B -->|Paragraph| E["<p>"]
    B -->|List| F["<ul>, <ol>"]
    B -->|Navigation| G["<nav>"]
    B -->|Article| H["<article>"]
    B -->|Section| I["<section>"]
    B -->|Generic container| J["<div>"]
    
    C --> K[Screen readers announce as main title]
    D --> L[Creates proper heading hierarchy]
    E --> M[Provides proper text spacing]
    F --> N[Enables list navigation shortcuts]
    G --> O[Identifies navigation landmarks]
    H --> P[Marks standalone content]
    I --> Q[Groups related content]
    J --> R[Use only when no semantic tag fits]
    
    style C fill:#4caf50
    style D fill:#4caf50
    style E fill:#4caf50
    style F fill:#4caf50
    style G fill:#2196f3
    style H fill:#2196f3
    style I fill:#2196f3
    style J fill:#ff9800

This approach makes your websites more accessible to users with disabilities and helps search engines better understand your content. It's a fundamental principle of modern web development that creates better experiences for everyone.

Adding a Semantic Page Title

Let's add a proper heading to your terrarium page. Insert this line right after your opening <body> tag:

html

<h1>My Terrarium</h1>

Why semantic markup matters:

Helps screen readers navigate and understand page structure
Improves search engine optimization (SEO) by clarifying content hierarchy
Enhances accessibility for users with visual impairments or cognitive differences
Creates better user experiences across all devices and platforms
Follows web standards and best practices for professional development

Examples of semantic vs. non-semantic choices:

Purpose	✅ Semantic Choice	❌ Non-Semantic Choice
Main heading	`<h1>Title</h1>`	`<div class="big-text">Title</div>`
Navigation	`<nav><ul><li></li></ul></nav>`	`<div class="menu"><div></div></div>`
Button	`<button>Click me</button>`	`<span onclick="...">Click me</span>`
Article content	`<article><p></p></article>`	`<div class="content"><div></div></div>`

🎥 See It in Action: Watch how screen readers interact with web pages to understand why semantic markup is crucial for accessibility. Notice how proper HTML structure helps users navigate efficiently.

Creating the Terrarium Container

Now let's add the HTML structure for the terrarium itself – the glass container where plants will eventually be placed. This section demonstrates an important concept: HTML provides structure, but without CSS styling, these elements won't be visible yet.

The terrarium markup uses descriptive class names that will make CSS styling intuitive and maintainable in the next lesson.

Task: Add the Terrarium Structure

Insert this markup above the last </div> tag (before the closing tag of the page container):

html

<div id="terrarium">
	<div class="jar-top"></div>
	<div class="jar-walls">
		<div class="jar-glossy-long"></div>
		<div class="jar-glossy-short"></div>
	</div>
	<div class="dirt"></div>
	<div class="jar-bottom"></div>
</div>

Understanding this terrarium structure:

Creates a main terrarium container with a unique ID for styling
Defines separate elements for each visual component (top, walls, dirt, bottom)
Includes nested elements for glass reflection effects (glossy elements)
Uses descriptive class names that clearly indicate each element's purpose
Prepares the structure for CSS styling that will create the glass terrarium appearance

🤔 Notice Something?: Even though you added this markup, you don't see anything new on the page! This perfectly illustrates how HTML provides structure while CSS provides appearance. These <div> elements exist but have no visual styling yet – that's coming in the next lesson!

mermaid

flowchart TD
    A[HTML Document] --> B[Document Head]
    A --> C[Document Body]
    B --> D[Title Element]
    B --> E[Meta Charset]
    B --> F[Meta Viewport]
    C --> G[Main Heading]
    C --> H[Page Container]
    H --> I[Left Container with 7 plants]
    H --> J[Right Container with 7 plants]
    H --> K[Terrarium Structure]
    
    style A fill:#e1f5fe
    style B fill:#fff3e0
    style C fill:#e8f5e8
    style H fill:#f3e5f5

🔄 Pedagogical Check-in

HTML Structure Mastery: Before moving forward, ensure you can:

✅ Explain the difference between HTML structure and visual appearance
✅ Identify semantic vs. non-semantic HTML elements
✅ Describe how proper markup benefits accessibility
✅ Recognize the complete document tree structure

Testing Your Understanding: Try opening your HTML file in a browser with JavaScript disabled and CSS removed. This shows you the pure semantic structure you've created!

GitHub Copilot Agent Challenge

Use the Agent mode to complete the following challenge:

Description: Create a semantic HTML structure for a plant care guide section that could be added to the terrarium project.

Prompt: Create a semantic HTML section that includes a main heading "Plant Care Guide", three subsections with headings "Watering", "Light Requirements", and "Soil Care", each containing a paragraph of plant care information. Use proper semantic HTML tags like <section>, <h2>, <h3>, and <p> to structure the content appropriately.

Learn more about agent mode here.

Explore HTML History Challenge

Learning About Web Evolution

HTML has evolved significantly since Tim Berners-Lee created the first web browser at CERN in 1990. Some older tags like <marquee> are now deprecated because they don't work well with modern accessibility standards and responsive design principles.

Try This Experiment:

Temporarily wrap your <h1> title in a <marquee> tag: <marquee><h1>My Terrarium</h1></marquee>
Open your page in a browser and observe the scrolling effect
Consider why this tag was deprecated (hint: think about user experience and accessibility)
Remove the <marquee> tag and return to semantic markup

Reflection Questions:

How might a scrolling title affect users with visual impairments or motion sensitivity?
What modern CSS techniques could achieve similar visual effects more accessibly?
Why is it important to use current web standards instead of deprecated elements?

Explore more about obsolete and deprecated HTML elements to understand how web standards evolve to improve user experience.

Post-Lecture Quiz

Post-lecture quiz

Review & Self Study

Deepen Your HTML Knowledge

HTML has been the foundation of the web for over 30 years, evolving from a simple document markup language to a sophisticated platform for building interactive applications. Understanding this evolution helps you appreciate modern web standards and make better development decisions.

Recommended Learning Paths:

HTML History and Evolution
- Research the timeline from HTML 1.0 to HTML5
- Explore why certain tags were deprecated (accessibility, mobile-friendliness, maintainability)
- Investigate emerging HTML features and proposals
Semantic HTML Deep Dive
- Study the complete list of HTML5 semantic elements
- Practice identifying when to use <article>, <section>, <aside>, and <main>
- Learn about ARIA attributes for enhanced accessibility
Modern Web Development
- Explore building responsive websites on Microsoft Learn
- Understand how HTML integrates with CSS and JavaScript
- Learn about web performance and SEO best practices

Reflection Questions:

Which deprecated HTML tags did you discover, and why were they removed?
What new HTML features are being proposed for future versions?
How does semantic HTML contribute to web accessibility and SEO?

⚡ What You Can Do in the Next 5 Minutes

Open DevTools (F12) and inspect the HTML structure of your favorite website
Create a simple HTML file with basic tags: <h1>, <p>, and ``
Validate your HTML using the W3C HTML Validator online
Try adding a comment to your HTML using

🎯 What You Can Accomplish This Hour

Complete the post-lesson quiz and review semantic HTML concepts
Build a simple webpage about yourself using proper HTML structure
Experiment with different heading levels and text formatting tags
Add images and links to practice multimedia integration
Research HTML5 features you haven't tried yet

📅 Your Week-Long HTML Journey

Complete the terrarium project assignment with semantic markup
Create an accessible webpage using ARIA labels and roles
Practice form creation with various input types
Explore HTML5 APIs like localStorage or geolocation
Study responsive HTML patterns and mobile-first design
Review other developers' HTML code for best practices

🌟 Your Month-Long Web Foundation

Build a portfolio website showcasing your HTML mastery
Learn HTML templating with a framework like Handlebars
Contribute to open source projects by improving HTML documentation
Master advanced HTML concepts like custom elements
Integrate HTML with CSS frameworks and JavaScript libraries
Mentor others learning HTML fundamentals

🎯 Your HTML Mastery Timeline

mermaid

timeline
    title HTML Learning Progression
    
    section Foundation (5 minutes)
        Document Structure: DOCTYPE declaration
                         : HTML root element
                         : Head vs Body understanding
        
    section Metadata (10 minutes)
        Essential Meta Tags: Character encoding
                           : Viewport configuration
                           : Browser compatibility
        
    section Content Creation (15 minutes)
        Image Integration: Proper file paths
                         : Alt text importance
                         : Self-closing tags
        
    section Layout Organization (20 minutes)
        Container Strategy: Div elements for structure
                          : Class and ID naming
                          : Nested element hierarchy
        
    section Semantic Mastery (30 minutes)
        Meaningful Markup: Heading hierarchy
                         : Screen reader navigation
                         : Accessibility best practices
        
    section Advanced Concepts (1 hour)
        HTML5 Features: Modern semantic elements
                      : ARIA attributes
                      : Performance considerations
        
    section Professional Skills (1 week)
        Code Organization: File structure patterns
                         : Maintainable markup
                         : Team collaboration
        
    section Expert Level (1 month)
        Modern Web Standards: Progressive enhancement
                            : Cross-browser compatibility
                            : HTML specification updates

🛠️ Your HTML Toolkit Summary

After completing this lesson, you now have:

Document Structure: Complete HTML5 foundation with proper DOCTYPE
Semantic Markup: Meaningful tags that enhance accessibility and SEO
Image Integration: Proper file organization and alt text practices
Layout Containers: Strategic use of divs with descriptive class names
Accessibility Awareness: Understanding of screen reader navigation
Modern Standards: Current HTML5 practices and deprecated tag knowledge
Project Foundation: Solid base for CSS styling and JavaScript interactivity

Next Steps: Your HTML structure is ready for CSS styling! The semantic foundation you've built will make the next lesson much easier to understand.

Assignment

Practice your HTML: Build a blog mockup