Google Docs can be shared directly others Google Docs users by entering their email addresses in the sharing menu. You can also use the option for "anyone with the link" to view, comment on, or edit your document. But there is also an option to publish your document as a simple webpage that doesn't give people the option to make copies of your document or view it in the Google Docs editor. In the following video I demonstrate all of those options and explain the differences between them.
One thing that I didn't include in the video is that Google Classroom users can share documents by making an assignment and selecting "make a copy for each student."
