In this documentation following Objecives is explained.
A plugin or module is codes that modify or extends existing Cart21 in order to add new functionality to Cart21.
Static Plugin module : it is static to system(website), usually showing a set of data such as "product category, latest content.." for front pages by assigning to page positions (left, right, center) on the plugin edit form.
Example; showing product category , showing limited number of latest content.
Dynamic Plugin module : it is related to dynamic data of the website like added product or content to show on front pages and it is assignable to page positions from dynamic data edit form but static plıugin module is assignable on the plugin edit form.
a case example is one of the added product to show or highlight on home page.
Modifying Plugin : it is not assignable to page positon, it is just modify the existing codes for a purpuse.
positional or non-positional plugin
When a Static Plugin module is positional that means it is assignable to page postions. Otherwise it is non-positional plugin. Therefore on its edit form there would not be Page Position Tab.
it represents plugin category and the section that plugin affects and enable admin user to filter plugins by its related category.