You can share Dashboards outside of your organization in two ways:
Regardless of how you share, you can customize how much access others have to your data. People you share with can view all Preview Cards on your Dashboard, and click into cards to see the detailed Charts. You can toggle: 1) whether or not others can view drilldowns, 2) whether drilldowns contain customer names or are anonymized, and 3) whether others can download your data.