Collaboration is a feature of Qualtrics that allows you to give someone else access to your survey, but limit what they can do.
Sharing is a set of features that allow you to share reports that you create in the View Results tab (but not the Reporting tab). There are two ways to do this:
1) Export the results to Excel, Word, PDF, or Powerpoint file
2) Publishing the report publicly to the web. The report
IMPORTANT: When using sharing of any kind, always consider whether the data is appropriate to share.