To fully understand the process, in MS Office 365, don't I have the capability to share a working document where others have 'edit/update' capabilities? Is the document maintained in the cloud for all users to mutually use once I share a 'link' to the document? Is this similar to the way Google spreadsheets can be used?
in order to use this functionality, the document needs to be stored either on Sharepoint or on OneDrive. Then you can share a link with other users, where you can decide if the document is editable for them or read-only.
From that moment, everybody can work within this document at the same time, and you even can "see" the other users while navigation through your spreadsheet.