Files with the DOCX extension are documents created with Microsoft Word 2007, the word processor included in Microsoft Office. They contain various elements such as images, drawn objects, tables, links to websites and to other local files and also feature a wide variety of text formatting options and styles.
The DOCX format is used worldwide and it's currently the most popular text document format. With the release of Microsoft Office 2007, it has become the default format for saving Microsoft Word documents.
DOCX files are based on the Open XML format which stores all content in a zipped archive. The archive contains XML and RELS files stored in three separate folders named “docProps”, “word” and "_rels". Files with the RELS extension dictate how the parts of the document connect to form a single file. This archived approach makes file content more accessible. For example images and text are stored individually within the archive.
How to open DOCX files
The contents of a DOCX file can be extracted individually by opening it with a data compression application (i.e. WinZip or WinRAR). The XML files of a DOCX document can be opened with any basic text editor and any web browser.
Since DOCX files are used primarily for document sharing, they can be opened with a large number of applications including online word processors. There are also many DOCX converters available online which can be used to convert DOCX files to other formats such as DOC or PDF.