HTML5 introduced several new elements that provide more structure and better semantic meaning to web pages. Here are some of the key new elements:

1. <article>

Represents independent, self-contained content, such as a blog post, a news article, or a forum post.

2. <section>

Defines sections within a document, such as chapters or groupings of content.

3. <nav>

Specifies navigation links.

4. <header>

Represents introductory content or a group of navigational links.

5. <footer>

Represents the footer of a document or a section. It typically contains information like copyright, contact information, or links to privacy policies.

6. <aside>

Represents content that is tangentially related to the content around it, such as a sidebar.

7. <mark>

Used to highlight text that is of special relevance or importance.

8. <progress>

Represents the progress of a task, like a progress bar. It is commonly used to show the progress of file uploads or downloads.

9. <summary>

Defines a heading for the <details> element. It is the clickable part that can be expanded or collapsed.

10. <figure>

Represents self-contained content that can be independently referenced, like an image, diagram, or illustration.

11. <figcaption>

Provides a caption or description for the content within a <figure>.

12. <datalist>

Contains a set of <option> elements that represent predefined options for an <input> element. It helps in providing suggestions to the user.