Finishing a document properly means saving, printing, and often sharing it as a PDF instead of the original file.
.docx is Word's native format — it keeps every formatting feature, and reopens exactly as you left it, in Word or in a compatible alternative.
File → Save As → choose PDF (or Export → Create PDF/XPS). A PDF looks identical on any device and can't be accidentally edited — the reason job applications and official documents are almost always sent as PDF, not .docx.
Ties back to Computer Basics
.pdf was already in the extension table back in File and Folder Basics — this is exactly what it's for.
Word periodically saves an AutoRecover copy in the background, separate from a manual save — if the program or computer crashes, reopening Word usually offers to restore that recovered copy. It's a safety net, not a replacement for pressing Ctrl+S regularly.