HTML5 Syntax and Structure

Doctype Declaration: Begins with <!DOCTYPE html> to specify HTML5.
Basic Structure:
- <html>: Root element.
- <head>: Contains meta-information, title, and links to styles/scripts.
- <body>: Contains the content of the webpage.
Elements and Tags:
- Tags are used to create elements, e.g., <p>, <div>, <a>.
- Most tags have opening and closing versions (e.g., <h1>...</h1>).
- Self-closing tags exist for void elements (e.g., <br>, <img>).
Attributes: Extra information in tags, e.g., <a href="url">.
Comments: Written as  for code annotations.

Definition: Elements that convey meaning about their content.
Key Semantic Elements:
- <header>: Introductory content or navigational links.
- <nav>: Links for navigating the webpage.
- <main>: Dominant content of the document.
- <article>: Independent content, e.g., blog posts.
- <section>: Thematic grouping of content.
- <aside>: Content related tangentially to the main content (e.g., sidebars).
- <footer>: Closing content or information about the content above.
Benefits:
- Improves accessibility (screen readers can better navigate).
- Enhances Search Engine Optimization (SEO).

Definition: Approach to ensure webpage looks good on all devices.
Viewport Meta Tag:
- Use <meta name="viewport" content="width=device-width, initial-scale=1.0"> to control layout on mobile browsers.
CSS Media Queries: Used alongside HTML5 to adapt styles based on device characteristics (screen size, resolution).
Flexible Grid Layouts: Use percentages rather than fixed dimensions for fluid layouts.
Responsive Images:
- Use the <picture> element or srcset attribute for different image resolutions.
Frameworks: Popular frameworks like Bootstrap help in creating responsive layouts quickly.

HTML5 documents begin with the <!DOCTYPE html> declaration.
The basic structure includes:
- <html>: The root element.
- <head>: Contains meta-information, the title, and links to stylesheets and scripts.
- <body>: Contains the visible content of the webpage.
HTML uses tags (e.g., <p>, <h1>, <a>) to create elements.
- Tags typically have opening and closing tags, like <p>This is a paragraph</p>.
- Void elements (like <br>, <img>) are self-closing, for example, <br>.
Attributes provide additional information within tags, such as <img src="image.jpg"> where src is an attribute.
Comments within HTML are written as .

Semantic HTML5 elements convey meaning about their content and enhance the web page's structure for both users and search engines.
Key semantic elements:
- <header>: Contains introductory content and navigational links.
- <nav>: Links for navigating the webpage.
- <main>: Encloses the main content of the document.
- <article>: Represents independent content, typically found in blogs or news articles.
- <section>: Groups thematically related content.
- <aside>: Contains content related to, but tangential to, the main content (e.g., sidebars).
- <footer>: Closing content or additional information about the content above.
Benefits of using semantic HTML5 elements:
- Improved accessibility (screen readers can better understand the page structure).
- Enhanced search engine optimization (SEO) by clarifying content organization.

Responsive design ensures that a webpage looks good on all devices (desktops, tablets, mobiles).
The viewport meta tag (<meta name="viewport" ...>) is essential for responsive design, using it allows you to control the layout on mobile browsers.
CSS media queries are used alongside HTML5 to adapt styles based on device characteristics (screen size, resolution).
Fluid layouts use percentages rather than fixed dimensions for elements, which makes the webpage adapt to different screen sizes.
Responsive images:
- Use the <picture> element or the srcset attribute to provide different image resolutions for different screen sizes.
Popular frameworks like Bootstrap help simplify responsive design for web developers.