How do you define a comment in HTML?

In HTML, comments are defined using the syntax <!-- comment here -->. This structure allows developers to add notes or remarks within the HTML code that will not be displayed in the browser when the page is rendered. Comments are useful for explaining sections of code, leaving reminders, or temporarily disabling code without deleting it.

Using this specific syntax is crucial because it adheres to the standards set by HTML, ensuring that the markup is correctly interpreted by web browsers. The opening tag <!-- indicates the beginning of a comment, while the closing tag --> marks the end of the comment. Anything placed between these tags will be ignored by the browser, making it a safe way to include non-displayed text within your HTML documents.