A PDF is designed to look the same everywhere, which makes it hard to edit. Converting it to Word rebuilds the text, tables and images as a document you can change.
Check whether the PDF has real text
Try to select a word with your mouse. If it highlights, the PDF has text and will convert well. If not, it is a scan and needs OCR first.
Convert it
Open PDF to Word, add the file and run the conversion. You get a DOCX file that opens in Word, Google Docs or LibreOffice.
Fix what does not carry over
Complex layouts, multi-column pages and decorative fonts can shift. Check tables and headings first, since these are the most likely to need a small fix. Text content is almost always intact.
When to use Word to PDF instead
If you only need to share a document, keep it as a PDF. When you need someone to edit a file you wrote, send it as Word and convert back with Word to PDF after the edits.