Doctype Declaration in HTML
What is a Doctype Declaration?
A doctype declaration is an instruction to the web browser about what version of HTML the page is written in. It's the first line of code in an HTML document and looks like this:
HTML
<!DOCTYPE html>
Why is it Important?
- Standardization: Ensures that different browsers interpret the HTML code consistently.
- Rendering Mode: Tells the browser to use the appropriate rendering mode (Standards mode or Quirks mode). Standards mode is generally preferred as it offers better compatibility and support for modern web technologies.
Common Doctype Declarations
While there are various doctype declarations for different HTML versions, the most common one used today is:
HTML
<!DOCTYPE html>
Historical Context
In older HTML versions (HTML 4), doctype declarations were more complex and involved referencing a Document Type Definition (DTD). However, with the introduction of HTML5, the process was simplified.
Key Points
- The doctype declaration should always be the first line of your HTML document.
- Using the correct doctype declaration is essential for consistent rendering across different browsers.
- For modern web development,
<!DOCTYPE html>is the standard choice.
Example of a basic HTML structure with a doctype declaration:
HTML
<!DOCTYPE html>
<html>
<head>
<title>My Web Page</title>
</head>
<body>
<h1>Hello, world!</h1>
</body>
</html>
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