This type of column is used to identify a row, it cannot be empty and is used as a display value in case the row is referenced elsewhere.It can be easily identified by the little blue key displayed in the column header:
This type of column is used to symbolize a link with another Sheet.It can be easily identified by the blue chips representing selected rows of the other Sheet inside any cell of the column.Other types of columns are:
Text: A simple text column.
Number: A number column.
Boolean: A boolean column taking form of a checkbox.
Filters can be applied to a column by clicking on the filter icon in the column header.Alphabetical filters sorting is also available by clicking anywhere inside the column header. A little arrow will show up to indicate the sorting direction.