I've worked alongside a dozen other people in one document. The thing that makes Google Docs so useful, however, is it's real-time collaboration, which works seamlessly with multiple users. Google Docs doesn't look at all like Microsoft Office, and has a very different user interface, but it does have many of the same, familiar features you know from Office. The changes will be made when your Mac is back online. There is a Google Drive app you can download onto Mac so you can work offline. Just visit the web-based app from your browser and you can create word processor documents, spreadsheets, and presentations.
If you have a Gmail account, or a Google Hangouts account, or a YouTube account, you have Google Docs. Google Docs is the easiest replacement for Microsoft office because it's so accessible.
