What are H1, H2, and H3 tags?

H1, H2, and H3 tags are HTML elements used to structure and organize content on web pages. They are part of the HTML heading hierarchy and are used to denote different levels of headings. Here's an overview of each:

1. **H1 Tag**: The H1 tag is the highest level heading tag in HTML and is typically used to denote the main heading or title of a page. It represents the most important piece of content on the page and is often the first thing users see when they land on a webpage. It's recommended to have only one H1 tag per page to clearly indicate the primary topic or subject matter.

   Example:
   ```html
   <h1>Main Heading</h1>
   ```

2. **H2 Tag**: The H2 tag is the second-level heading tag and is used to denote subheadings or sections within the content of a webpage. H2 tags are typically used to break down the main topics or sections of the page into smaller, more manageable sections.

   Example:
   ```html
   <h2>Subheading 1</h2>
   ```

3. **H3 Tag**: The H3 tag is the third-level heading tag and is used to denote sub-subheadings or subsections within the content of a webpage. H3 tags are often used to further break down the content under H2 headings into smaller, more specific topics or sections.

   Example:
   ```html
   <h3>Sub-subheading 1</h3>
   ```

Heading tags are not only important for structuring content in HTML but also for SEO purposes. Search engines use heading tags to understand the hierarchy and relevance of content on a webpage. Properly using heading tags can help improve the accessibility, readability, and SEO performance of your website.