Final answer:
XHTML is the HTML version that follows XML syntax and rules, requiring elements to be properly nested and closed, ensuring cross-browser compatibility and presentation quality.
Step-by-step explanation:
The version of HTML that utilizes XML syntax and requires strict adherence to rules is called XHTML (Extensible Hypertext Markup Language). In creating websites, XHTML combines the flexibility of HTML with the strictness of XML, demanding that all elements be properly nested, closed, and well-formed. This means that while designing a webpage with XHTML, tags should be in lowercase, attributes must be quoted, and elements like br and img need to be self-closing.
Taking care to write valid XHTML is crucial in ensuring that webpages are correctly displayed across different browsers and platforms. Moreover, careful HTML formatting contributes to how information is presented, making it easy to digest and aesthetically pleasing. The balance and choice of tools are essential for creating effective web content without overcomplicating the user experience.