What is the goal of Dashboards?

Dashboards are an effective tool using which the management can have an overview of their entire business. It is a quick snapshot of how the business is going.It helps the management to assess and predict different levels of business activities.

to consolidate data from different sources and provide useful information to support decision decisions. 

The simplest example is when looking at sales operations.  Metrics such as bookings vs. quota, rep performance, individual product categories, customer behavior and demographics, can be monitored separately, together, or as part of broader initiatives.  The value this brings to the business is significant.

Dashboards are designed as per the requirement of target audience. For example an operational manager would want to keep tracks of his/her area of responsibilities and his requirements will be completely different from a Commercial Team member, In the same member company's board of director would be interested in overall performance of the company. But there is one thing common in all of these they all want to know/track all their required information in a single glance. That's the goal of Dashboard to fulfill the requirement of target audience in a manner that satisfies their need.