What is the default file format when saving a Word document?

The default file format when saving a Word document is .docx. This format was introduced in Microsoft Office 2007 and has since become the standard for Word documents. It is based on the Open XML format, which allows for better data recovery and smaller file sizes compared to the previous .doc format. The .docx format also supports more advanced features, such as improved integration with web technologies and enhanced graphical capabilities.

When saving documents in .docx, users benefit from compatibility with other software that supports this format while preserving formatting, images, and other elements of the document. The .docx extension indicates that the document may contain multiple XML files stored in a compressed ZIP package, making it easier for applications to read and manipulate the content.

Other file formats, like .txt, .pdf, and .rtf, do have their specific uses, such as text documents, portable formats for sharing, and rich text formats, respectively, but they do not represent the default option for saving Word documents within the Microsoft Word application.