In Microsoft Word, when you open a new document without saving it, Word automatically names it Document-1. If you create more new documents, they’ll be labeled Document-2, Document-3, and so on until you save them with your own name.
This naming system acts as a temporary placeholder to help you tell multiple unsaved files apart during the same session. Word creates these sequential names—starting with “Document1”—from a temporary template, increasing the number each time you open a new file so every window has a unique label in the taskbar and the “Window” menu. These titles exist only temporarily and aren’t stored on your computer until you use Save or Save As, at which point your chosen file name replaces the generic one.