The <html> tag
After the <!DOCTYPE html> goes the <html> tag — the cornerstone of any web page. Like all tags, it starts and ends with an angle bracket. With <html>, the closing </html> tag creates an obligatory frame that marks your document's borders.
One more thing to remember — the HTML isn't case sensitive, and you can write it whichever way you like <html> or <HTML>. Remember to keep it consistent and use either lowercase or uppercase.
