What is represented by the semantic elements in markup?

Semantic elements in markup, such as HTML, play a crucial role in conveying meaning and context to both browsers and assistive technologies. When content is marked up semantically, it conveys relationships and structures inherent in the data. These elements (like <header>, <article>, <section>, <nav>, etc.) are not solely about how the content looks (visual styles) but rather about the significance and organization of that content within the webpage.

For instance, an <article> tag indicates that the enclosed content is a self-contained composition that can be distributed independently. This helps search engines and screen readers understand that this part of the content has specific meaning and contextual relevance. Similarly, the use of <nav> signifies navigation links, guiding both users and assistive technologies regarding the site's structure.

In contrast, visual styles are controlled separately through CSS and don’t contribute to the semantic understanding of the document. Functional keywords are related more to programming languages or specific libraries, and layout templates focus on design rather than the meaning conveyed by markup. Thus, the emphasis on relationships and structures demonstrates the importance of semantic elements in informative content accessibility and communication.