The default word processor on Mac is Pages. Over the years, it has evolved into a powerful word-processor with features that are competent enough to stand as a replacement for MS Word. Word documents created on Pages can be opened, by default, on other Macs only (or in iWork in the cloud). If you want your document (created in Pages) to be accessible to anyone (especially, MS-Word users), you have to save Pages files in the “.doc” or “.docx” format.
Since Microsoft's Word is one of the most popular word processors in the world, and since the “.doc” format is far more universally compatible, it makes more sense to convert or export your documents in the same format. Pages, fortunately, lets you export to these formats easily.
Here is How to Save Pages Files as Word Document Format from a Mac:
Step 1: In the Pages app, open the file you want to convert into a MS-Word document.
Step 2: From the menubar, click on File → Export To.
Step 3: Then, click on Word.
Step 5: Now, choose the appropriate extension – “.docx” or “doc.”
Step 6: Click on Next.
Step 7: Type a name for the word document, pick a destination, and click Export.
Tip: “.docx” version is used for the newer versions of word document. The “.doc” format is compatible with almost all versions including support for older ones.
Incidentally, you can do the same with iCloud Pages too. The only difference is that instead of an export, you will be “downloading” the document. When you download, you have the option to pick a format (Pages, PDF or Word). Selecting “word” will export/download your document in “.doc” format.