What are HTML and CSS primarily used for?

HTML (HyperText Markup Language) and CSS (Cascading Style Sheets) are primarily utilized for structuring and styling web pages. HTML provides the foundational elements of a webpage, allowing developers to define the layout and content, such as headings, paragraphs, images, and links. CSS, on the other hand, is employed to define the visual appearance of these HTML elements, including colors, fonts, layout, and overall aesthetics.

By using HTML and CSS together, developers can create visually appealing and well-organized web content. This combination is essential for front-end web development, providing the necessary tools to ensure that web pages are not just functional but also attractive and user-friendly. The focus on structuring the content with HTML and styling it with CSS is a core principle in creating effective web interfaces.

Other choices involve technologies or concepts that do not pertain directly to HTML and CSS. Databases and managing user data relate more closely to back-end development, while mobile application development often encompasses different programming languages and frameworks. Similarly, writing server-side code typically involves languages like Python, Ruby, or PHP rather than HTML and CSS.