Datasets function as an additional layer between Data Sources and elements created in Metric Insights. This functionality gives users without a technical background the ability to utilize data. With Datasets there is no need to understand the structure of source database, know SQL or the syntax of other BI tools. Datasets allow:

• Data to be easily staged to support business users in creating their own Metric Insights content without having to understand underlying Data Sources
• Snapshots of data from a Data Source without having to create and maintain "staging reports".
• Creation of exception and change reports from any Data Source without having to understand Data Source-specific syntax or SQL   See also Dataset/User Map Security Overview  (Release 5.2.1 and beyond)
• Utilization of dynamic filtering to identify exceptions and changes in large, complex data sets without any dimensional restrictions

For more details refer to: Create a Dataset