In short
This tool displays a Word document (.docx) without Word installed, on a computer or a phone: to read an attachment, or to review a document before passing it on or printing it. Pages are displayed with their layout, headers, footers and notes included; comments and tracked changes are not shown, and the pagination may differ from Word's. Dangerous links are disabled; the others open in a new tab. From the preview, you can print the document or save it as PDF, extract its text, or open it in the “Document” editor to edit it. Only the .docx format is read, not the old .doc. The document is displayed by your browser and stays on your device.