2021-12-14T18:15:05Z
A document fragment, colloquially, is what it sounds like, except in XML (and adjacent) parlance it takes on an additional specific meaning. That is, a document fragment consists of one or more nodes like text or markup elements (tags). Thus, a concrete representation (e.g. a file) of a document fragment would itself be valid markup, and not start or end in the middle of a tag. (XML documents go further and require exactly one root element.)
document fragment
fragment