The standard file format for documents created in Microsoft Word is DOCX. Introduced in Word 2007, this format utilizes XML to store document information, allowing for better data management and smaller file sizes compared to the previous format, .DOC. DOCX supports rich text formatting, images, tables, and multimedia elements, making it versatile for various document types, from reports to resumes. As a widely recognized standard, DOCX ensures compatibility across different platforms and devices, facilitating easy document sharing and editing.