HTML for Beginners: Understanding the Declaration
Micro Lesson 01 The <!DOCTYPE html> Line Quick Definition This is a document type declaration . It tells the web browser that your file is a modern HTML5 webpage. Without this line, browsers might enter "Quirks Mode," which can cause your website to look broken or behave inconsistently. Code Example 1 2 <!DOCTYPE html> <html> Pro Tip: This must be the absolute first line in your HTML document—even before the <html> tag!