Basic modules are meant to be "bricks" of the visual builder. They are static (at least at the moment). You can use them to add useful information about the product, increase the visual appearance of the single product page etc.
Everything starts from a row :) It is the first of the two fundamental building blocks. Rows can only hold columns.
It is the second of the two fundamental building blocks. Columns can be placed in rows only. Only columns can hold modules/options.
Use it to add custom text. A variety of HTML tags can be used here.
Basically, it is just a nice looking link :)
Use this module if you need to add an image to builder content.