HTML <main>标记指定文档中的主要或重要内容。每页只能使用一次，并且不能用作<article>，<aside>，<footer>，<header>，<nav>元素的后代。
您可以尝试运行以下代码，以了解如何在HTML文档中显示主要内容-
<!DOCTYPE html> <html> <body> <main> <h1>Learning</h1> <p>Learn to gain experience and try to share your knowledge with others.</p> <article> <h3>Web Development Tutorials</h3> <p>Consist of CSS, HTML, and PHP tutorials for 2nd Semester exams.</p> </article> <article> <h3>Academic Tutorials</h3> <p>Consist of Computer Fundamental, Computer Network tutorials for 1st Semester exams.</p> </article> </main> </body> </html>