CloudSuite is Collabora's version of LibreOffice in the cloud and comes with built-in collaborative editing. It allows editing and accessing online documents that can also be shared easily across users. Whole teams can collaboratively edit text documents, spreadsheets, and presentations. You can access and modify the shared documents through a web interface, directly from the LibreOffice desktop suite, or even from Collabora's own Android LibreOffice app.
Of course CloudSuite supports the full range of document formats LibreOffice does. That includes, among many others, the ISO-approved native Open Document formats, and most, if not all, Microsoft Office formats.
What with Kolab also gaining collaborative editing of text documents (already available), and emails, notes, calendars, and contacts over the next few months, you're probably seeing where this is going: by combining Kolab with Cloudsuite, the aim is to integrate a suite of office tools, each and all of which, from the email client to the presentation editor, can be used collaboratively and online by all the users of a team. And we'll be doing it using exclusively free and open sourced technologies and open standards.
So, to summarize with of a tongue twister: Kolab & Collabora collaborate on collaboration.