DOCTYPEmäärityksellä
The DOCTYPE declaration, often shortened to DOCTYPEmääritys in Finnish, is a mandatory instruction that must be placed at the very beginning of an HTML or XHTML document. Its primary purpose is to inform the web browser about the document type and version of HTML being used. This declaration is crucial for the browser to correctly interpret and render the page according to the specified standards.
Historically, DOCTYPE declarations were essential for enabling "standards mode" rendering in browsers. Without a proper DOCTYPE,
There are different types of DOCTYPE declarations, including those for HTML5, XHTML, and older HTML versions.