Column type widgets are used to modify/display the data for a cell in the table. It is somehow similar to the data type in Mysql. They are used to handle structured data.
The column type widget can be added similar to the section type widget. It has to be configured first for each table before using it. All records created for a table will have the same column widgets. See here for more details on how to configure column widgets.
Please see here for how to add a column.
When created, the cell value can be modified by clicking the "edit" icon. A corresponding form will be displayed, click "Submit" to update the value.
Some widgets come with additional functions. Click the icon next to it to run the functions.
Most of the column type widgets supports the batch actions in updating data. See here for more details.
See here for a list of column widgets.