DOCTYPEmääritys
DOCTYPEmääritys, often referred to as the DOCTYPE declaration, is a mandatory instruction that must appear at the very beginning of any HTML or XHTML document. Its primary purpose is to inform the web browser about the version of HTML or XHTML the document is written in, which in turn helps the browser render the page correctly by enabling standards-compliant rendering mode.
Without a DOCTYPE declaration, web browsers may enter quirks mode, a less strict rendering mode that emulates
The syntax of the DOCTYPE declaration varies depending on the HTML or XHTML version. For HTML5, it
In modern web development, using HTML5 and its streamlined DOCTYPE is the standard practice. It simplifies