Grouping your records will sort and break your data into meaningful groups. For example, you may want to display customers per region.
You can group information based on database fields, formula fields, or data that is not contained in your data source.
Once the data is grouped, you can also summarize the information in each group.
When you add a group, you add two new areas to your report - a Group Header and Group Footer section.
These new areas are clearly visible in the Design tab and they can be found in the left margin of the Preview tab. The Group Header and Group Footer surround the Details section.
A Group #n Name field is automatically created in the Group Header. This field can be removed without affecting the Group Header and Group Footer sections. You can also re-insert the field using the Field Explorer.