**HTML Revision Notes**
**1. Introduction to HTML:**
- HTML stands for HyperText Markup Language.
- It is used to structure content on the web, creating web pages and applications.
**2. HTML Basics:**
- Elements are enclosed in tags: `<tagname>content</tagname>`.
- Most HTML tags come in pairs: opening and closing tags.
- HTML5 uses `<!DOCTYPE html>` at the beginning to declare the version.
- Basic structure: `<html>` → `<head>` → `<title>` → `<body>`.
**3. Text and Formatting:**
- Headings: `<h1>` to `<h6>` for different levels of headings.
- Paragraphs: `<p>` for paragraphs of text.
- Emphasis: `<em>` for emphasis, `<strong>` for strong importance.
- Line Break: `<br>` for line breaks.
- Horizontal Rule: `<hr>` for thematic breaks.
**4. Links and Images:**
- Hyperlinks: `<a href="url">text</a>` for creating clickable links.
- Images: `<img src="image.jpg" alt="description">` to embed images.
**5. Lists:**
- Unordered Lists: `<ul>` → `<li>` for bullet-point lists.
- Ordered Lists: `<ol>` → `<li>` for numbered lists.
**6. Tables:**
- Table Structure: `<table>` → `<tr>` (table row) → `<td>` (table data) or `<th>` (table header).
- Table Headers: `<th>` for table header cells.
- Table Data: `<td>` for table data cells.
**7. Forms:**
- Form Structure: `<form action="server.php" method="POST">`.
- Input Fields: `<input type="text" name="fieldName">` for text inputs.
- Textarea: `<textarea name="areaName"></textarea>` for multiline text.
- Radio Buttons: `<input type="radio" name="radioGroup" value="value">`.
- Checkboxes: `<input type="checkbox" name="checkGroup" value="value">`.
- Dropdown: `<select name="dropdownName">` → `<option value="value">Text</option>`.
**8. Semantic Elements:**
- Semantic tags provide meaning to the structure: `<header>`, `<nav>`, `<main>`, `<article>`, `<section>`, `<aside>`, `<footer>`.
**9. Multimedia:**
- Audio: `<audio controls>` → `<source src="audio.mp3" type="audio/mpeg">`.
- Video: `<video controls>` → `<source src="video.mp4" type="video/mp4">`.
**10. IFrames:**
- Inline Frames: `<iframe src="page.html"></iframe>` to embed another webpage.
**11. Meta Information:**
- `<meta charset="UTF-8">` for character encoding.
- `<meta name="viewport" content="width=device-width, initial-scale=1.0">` for responsive design.
**12. Comments:**
- `<!-- This is a comment -->` for adding comments in the code.
**13. Best Practices:**
- Use proper indentation and consistent naming conventions.
- Separate content, presentation, and behavior (use CSS and JavaScript).
- Test your code on different browsers for cross-compatibility.
**14. Further Learning:**
- Explore more HTML tags and attributes.
- Learn CSS for styling and JavaScript for interactivity.
- Keep practicing by building simple web pages.
Of course! Here's some additional information to supplement your HTML revision notes:
**15. HTML Document Structure:**
- The `<!DOCTYPE html>` declaration specifies the document type and version.
- The `<html>` element is the root of the HTML document.
- The `<head>` section contains metadata and links to external resources.
- The `<title>` element sets the title displayed in the browser's tab.
- The `<body>` section holds the visible content of the web page.
**16. Text Formatting:**
- Semantic Markup: Use tags like `<em>` and `<strong>` for meaningful emphasis.
- `<abbr>`: Represents an abbreviation or acronym with a title.
- `<sup>`: Renders text as superscript (e.g., 2^nd^).
- `<sub>`: Renders text as subscript (e.g., H~2~O).
**17. Links and Attributes:**
- Link Attributes: `target="_blank"` opens a link in a new tab/window.
- Internal Links: Use `<a href="#section">` to link within the same page.
- Email Links: `<a href="mailto:email@example.com">` creates email links.
**18. Images and Attributes:**
- Image Alt Text: The `alt` attribute provides alternative text for screen readers and when images fail to load.
- Image Sizes: Use `width` and `height` attributes to specify image dimensions.
**19. Lists and Attributes:**
- `<dl>`: Definition list; pairs of `<dt>` (term) and `<dd>` (definition) elements.
- `<li>` Attributes: Use `value` attribute for ordered list numbering.
**20. Tables and Attributes:**
- `<caption>`: Adds a caption to the table.
- `<colgroup>`: Groups columns together for styling or other purposes.
- `<thead>`, `<tbody>`, `<tfoot>`: Groups table content for better organization.
**21. Forms and Attributes:**
- `<fieldset>`: Groups related form elements together.
- `<legend>`: Provides a caption for the `<fieldset>`.
- `<input>` Types: `date`, `email`, `url`, `number`, `range`, and more.
**22. Input Attributes:**
- `placeholder`: Provides a hint for expected input.
- `required`: Specifies that an input field must be filled before submission.
- `disabled`: Disables an input field.
**23. Form Controls:**
- `<select>`: Creates dropdown lists for selection.
- `<optgroup>`: Groups related options within a `<select>`.
- `<datalist>`: Provides pre-defined options for an `<input>` element.
- `<button>`: Creates clickable buttons.
**24. Semantic Elements (Continued):**
- `<figure>`: Groups media content (like images) with captions using `<figcaption>`.
- `<time>`: Represents dates and times, machine-readable by browsers.
- `<mark>`: Highlights text with a yellow background.
**25. Accessibility Considerations:**
- Use appropriate semantic elements for better accessibility.
- Add descriptive `alt` attributes to images.
- Provide textual alternatives for multimedia content (audio, video).
**26. Document Structuring:**
- Divide content logically using semantic elements like `<header>`, `<main>`, `<section>`.
- `<nav>`: Defines navigation links; usually in the header or footer.
**27. Miscellaneous:**
- Use inline styles for quick styling: `<tag style="property: value;">`.
- Avoid using deprecated elements and attributes (like `<font>`).
- Test your web pages on different browsers and devices.
**28. Version Considerations:**
- HTML5 introduced many new elements and attributes.
- Older versions (like HTML 4.01) had fewer semantic elements.
**29. Semantic Elements (Continued):**
- `<article>`: Represents a self-contained, complete composition, like a news article or blog post.
- `<section>`: Defines a section of content with a thematic grouping.
- `<aside>`: Contains content that is tangentially related to the main content.
- `<details>` and `<summary>`: Creates a disclosure widget to hide/show additional information.
- `<dialog>`: Represents a dialog box or popup.
- `<meter>`: Represents a scalar measurement within a known range, like a progress bar.
- `<progress>`: Represents the progress of a task, often used for loading bars.
**30. Multimedia (Continued):**
- Video Attributes: `controls`, `autoplay`, `loop`, `muted`, `poster`.
- Audio Attributes: Similar to video, including `controls`, `autoplay`, and `loop`.
**31. HTML Entities:**
- Use HTML entities for special characters that can't be directly typed, like `©` for © or `&` for &.
- Numeric character references: Use `😁` for a Unicode character (like 😀).
**32. Meta Tags:**
- `<meta name="keywords" content="keyword1, keyword2">`: Specifies keywords for search engines.
- `<meta name="description" content="Page description">`: Provides a brief description for search engines.
- `<meta name="robots" content="index, follow">`: Instructs search engines on indexing behavior.
- `<meta http-equiv="refresh" content="5;url=page.html">`: Automatically redirects after a set time.
**33. HTML Forms (Advanced):**
- Input Types: `color`, `datetime-local`, `month`, `time`, `week`, `search`, `tel`, `url`.
- `<input type="file">`: Allows file uploads.
- Form Validation: HTML5 provides native form validation using attributes like `required`, `min`, `max`, and `pattern`.
- `<datalist>`: Provides a list of pre-defined options for autocompletion.
**34. Accessibility (Continued):**
- Use semantic elements and proper headings to create a clear document outline.
- `<label>`: Associates a label with an input element, improving usability and accessibility.
- `aria-*` attributes: Enhance accessibility using attributes like `aria-label` or `aria-labelledby`.
**35. Advanced Attributes:**
- `contenteditable`: Makes an element editable by users.
- `spellcheck`: Enables or disables spell checking for editable elements.
- `draggable`: Allows elements to be draggable using HTML5's drag-and-drop API.
- `hidden`: Hides elements from view.
**36. Inline Frames (IFrames) (Continued):**
- `sandbox` attribute: Restricts the behavior of the embedded content.
- `allow` attribute: Specifies permissions for the embedded content.
- IFrames are commonly used to embed maps, videos, and external content.
**37. Web Storage (Local Storage and Session Storage):**
- HTML5 introduced Web Storage to store data on the client side.
- Local Storage: Persists data even after the browser is closed.
- Session Storage: Stores data for the duration of the session (until the browser is closed).
**38. Deprecated and Obsolete Elements:**
- Elements like `<center>`, `<font>`, and `<strike>` are no longer recommended.
- Avoid using deprecated elements in favor of modern alternatives and CSS styling.
**39. HTML5 APIs:**
- HTML5 introduced various APIs, like Geolocation, Web Workers, and WebSockets.
- Geolocation API: Retrieves the user's geographic location.
- Web Workers: Enables multitasking in JavaScript by running scripts in the background.
- WebSockets: Provides full-duplex communication channels over a single TCP connection.
**40. HTML5 Semantic Form Elements:**
- `<input type="email">`, `<input type="tel">`, `<input type="url">` for specific input validation.
- `<input type="number">`, `<input type="range">` for numeric inputs.
- `<input type="date">`, `<input type="time">`, `<input type="datetime-local">` for date and time inputs.
**41. HTML and SEO:**
- Structuring content using semantic elements can positively impact search engine optimization (SEO).
- Use meaningful `<title>` and `<meta>` tags to improve search engine visibility.
**42. Cross-Origin Resource Sharing (CORS):**
- Browsers enforce same-origin policy to prevent unauthorized access to resources.
- CORS allows servers to specify which origins are permitted to access resources.
HTML is just one part of web development. CSS is used for styling, and JavaScript is used for interactivity. Keep practicing and exploring these technologies to create dynamic and engaging web experiences.
Remember that web development is a vast field, and these notes provide a solid foundation. As technology evolves, it's important to keep learning and adapting your skills to stay current in the industry.
