A DOCX file is a document file format used by Microsoft Word, a popular word processing program. It is the standard file format for documents created in Microsoft Word from 2007 onwards. DOCX files contain text, formatting, images, and other elements that make up a document. They are known for their compatibility, allowing users to open and edit them in various word processing applications, including Microsoft Word, Google Docs, LibreOffice, and more. The "X" in DOCX stands for XML, which is the underlying technology used to store the document's data. This format offers improved data recovery and document structure compared to the older DOC format.