Dashboards is a feature that allows you to build reports for your personal use or for internal and external stakeholders. Dashboards can be up of any reports (tables and graphs) and dashboard elements (page breaks, sub headings, and text boxes).
Reports vs Dashboards
A report is an individual chart or table which shows the data you have specified by selecting categories and metrics, and by applying filters and a date range.
A dashboard is a collection of reports. Dashboards can be arranged in anyway to best display the data that you want to include for reviewing or reporting.
Simply put a dashboard is a collection of reports. What the dashboard looks like and what data is include is entirely up to you.