Can word open and edit documents created in pages

No. You have to export the file to Word format before sending it off to be edited. If you just want someone else to view it you might be better off sending them a PDF. If someone does edit the document to exported, you'll be able to import it into Pages. This has worked fine for me with documents with hundreds of pages. (No fancy formatting, though.)

Pages is not a Word clone, and when opening Word documents in it, they are translated into the internal Pages .pages document format. The original contents of the Word document are not changed. Another translation occurs on the export process back to Word. Your compability mileage will vary depending on the unique features used in Word and Pages.

You want to use Word files, use Word.

If you don't want to use Word, LibreOffice is a much better clone and it is free.

Peter