For the row type you can choose either the attribute or the group. The attribute type will create a row with compared attributes of each product. In the second column you choose which attribute exactly will be used for comparison. Lastly, you can enter a custom label for the row. If none entered, the default attribute name will be used.

Once you have the attributes selected, you can organize them into custom groups for the better overview. To do that, simply choose the group type and enter the group title in the custom label column.

To have a better idea how it works, please have a look at the below image and compare it to the settings image from the beginning of this article.