The classic dashboards are designed to report key performance indicators (KPIs). Think of the dashboard of a car or the cockpit of an airplane. The KPI dashboard is all about dials and numbers. Typically, these dashboards are live and show the latest numbers. In a business context, they typically show trend data as well.
A very simple example of a KPI Dashboard is below. Such dashboards can, of course, be huge. Huge dashboards have lots of pages crammed with numbers and charts, looking at all manner of operational and strategic data.
The single most important question I think you can ask about dashboards is, what does the intended audience need to see (and do, once they’ve seen)? That will drive the kind of dashboard elements you want to use. If you need people to react and perform some maintenance operation, you probably want a KPI chart. If you want to influence readers’ opinions, infographic elements might be the trick.