What is the purpose of a semantic tag in HTML?

A semantic tag in HTML serves the purpose of conveying the meaning and structure of the content it contains, making it more understandable for both browsers and developers. These tags are designed to describe not just how the content looks but what the content actually represents. For instance, using tags like <article>, <section>, and <header> helps search engines and screen readers interpret the content more effectively, improving accessibility and SEO.

Semantic tags enhance the clarity of the document structure, enabling better cooperation between the document's markup and the technologies that parse and utilize this information. This distinction is essential for creating web pages that are not only visually appealing but also meaningful in conveying information.

In contrast, the other options focus on formatting or grouping elements without addressing the importance of semantic meaning. For example, formatting text pertains to presentation rather than meaning, while grouping elements for data processing is concerned with functionality rather than how the content is interpreted. Defining interactive buttons and links centers on user interactions instead of the inherent meaning of the content. This underscores why semantic tags are pivotal in writing HTML that is both functional and meaningful.