Which is the best/proper way to declare the header for a page?

Using the <header> element to define the header for a page is aligned with HTML5 semantics and best practices. The <header> tag is specifically designed for introductory content or navigational links typically found at the top of a section or page. This specialization enhances the clarity and structure of the document.

Within the <header> element, the <h1> tag serves as the main heading, which is crucial for both user accessibility and SEO, indicating the most important title of the page. The <nav> element further signifies that the contents within it contain navigational links, improving the document's semantic structure. This not only helps with organizing the layout but also aids in search engine optimization and makes the content more understandable for screen readers and other assistive technologies.

In contrast, using a <div> to create a header lacks semantic meaning. While <div> is a generic container, it does not convey any information about its role in the document structure. Therefore, the use of semantic elements like <header> and <nav> promotes better coding practices, improves searchability, and enhances accessibility, making this approach the most effective way to declare a page's header.