When grouping is active, the grid can be collapsed or expanded by the grouped fields allowing you to summarise groups of records.
This is useful when you have a lot of records and you want to look at only a few if them.
Collapsing Groups
To collapse the grid

Simply click the "Collapse" button.

When a group is collapsed, only its summary information is visible.
Expand Groups
To Expand the Grid, Click the "Expand" button from the "Collapse" Drop Down


When expanded all data is visible