Description of Shopware variables

Hello everyone,
I’m trying to map out all the variables of the REST-API-Endpoints to the fields of our ERP-system. Since I’m not a pro yet, I am struggling finding descriptions of every single field, despite data types.
Hence my question: Is there any unambigious documentation of every single variable with some sort of description? Like a list or sth.?
Help is much appreciated!
Thanks a lot!
Cheers Patrick