Select the range of data
Go to the Data tab
Click Sort
Choose the column to group by
Click Add Level if grouping by multiple columns
Set the sort order
Click OK
Use Subtotal for grouped summaries
Select the data range
Go to the Data tab
Click Subtotal
Choose the column to group by
Select the summary function
Click OK
Use PivotTable for flexible grouping
Select the data range
Go to the Insert tab
Click PivotTable
Drag the field to Rows or Columns
Add values to summarize
Use Group in PivotTable for dates or numbers
Right-click a date or number field
Click Group
Choose the grouping options
Click OK
Use Outline Group for rows or columns
Select the rows or columns
Go to the Data tab
Click Group
Use Ungroup to remove grouping
Select the grouped rows or columns
Go to the Data tab
Click Ungroup