Understanding HTML Attributes: A Closer Look at fontSize

HTML, or Hypertext Markup Language, is the key foundational language used to create web pages. One of its primary constituents are HTML attributes. An attribute in HTML provides additional information or sets the property of an HTML tag. While there are many HTML attributes, one of the answer options in the given quiz, 'fontSize', is not an HTML attribute.

The 'fontSize' is actually a property used within CSS, or Cascading Style Sheets, the design language used in tandem with HTML to stylize and design web elements. For instance, if you're aiming to set the font size of a paragraph tag, you would use CSS:

p {
    font-size: 20px;
}

In this snippet, 'fontSize' is used as a CSS property, not an HTML attribute. It tells the browser how to render or display the paragraph text.

Now, let's take a look at the attributes that are indeed a part of HTML:

• alt: This attribute is used within an 'img' tag and provides an alternative text for an image if the image cannot be displayed. This has an added accessibility benefit for visually impaired users.
• target: Utilized within the 'a' tag, 'target' defines where to open the linked document. For example, a value of '_blank' opens the linked document in a new tab or window.
• id: This attribute assigns a unique identifier to an HTML element, which aids in linking, scripting, and styling.

In the context of best practices, it's important to remember that HTML attributes should be used correctly within their respective tags for expected behavior. Moreover, for a well-structured and validated website, keeping HTML strictly for structure and semantics, and using CSS for presentation, such as font sizes and color, promotes separation of concerns and often results in cleaner, easier to maintain code.

In conclusion, HTML attributes are critical for defining element properties but it's equally critical to not confuse them with CSS properties. Understanding these distinctions can help ensure robust and effective website development.