In recognition of National Cyber Security Awareness month, Google explains the Google Docs options for sharing your documents. In your document list, you'll notice various icons and descriptions listed next to the title of each doc. Here's a general overview: A lock icon means "Private"; A lock icon in front of a globe means "Anyone with the link"; A globe means "Public on the web".
Next to each of these icons, you'll see text indicating who can edit a doc and who can view a doc -- a collaborator is able to edit, while a viewer can access a doc in view-only mode.
Let's look at a few examples: