OneDrive for Business is SharePoint - it's the new new name for SharePoint Workspace to be more precise. Syncing with a SharePoint server in the MS cloud. It is thus a completely different thing from OneDrive (consumer) and why MS marketing chose to confuse it this way I guess we'll never understand.
SharePoint is a DMS not a filesystem, and it syncs document management metadata from, and to, the documents (depending on file format).
In container file formats this is done in metadata, not content, sections - your document content is not touched (try office documents with digital signatures - the signature will remain valid, because it validates the content areas of the file format, not metadata). In some file formats it will add comments in a way that does not affect the content (as above).
That is all this is, SharePoint on-premise will do exactly the same thing, and it is a documented SharePoint feature for at least a decade - see e.g. http://weblogs.asp.net/bsimser/archive/2004/11/22/267846.aspx