In HTML, the doctype is the required "<!DOCTYPE html>
" preamble found at the top of all documents. Its sole purpose is to prevent a browser from switching into so-called βquirks modeβ when rendering a document; that is, the "<!DOCTYPE html>
" doctype ensures that the browser makes a best-effort attempt at following the relevant specifications, rather than using a different rendering mode that is incompatible with some specifications.
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General Knowledge
Technical reference
- Document.doctype, a JavaScript method that returns the doctype