documentation for DataModelSchema from pbit

I exported a powerbi Desktop as a template and started looking at the resutling filles, DataModelSchema in particular

Reviewing the json, there is a bit I was able to understand, but equally, lots I have not been able to understand. Is there any documentation regarding this?

I am interested in interpretation of this section:

specifically, the Enitities and Relationships, which expand to:

Where an entity expands to:

which is a column in one of my tables, but what does each of these metadata mean ? What does the Type/State/Weight mean? How does it impact the file?

Similarly, Relationships expands to:

Is there a place where I can get a definition of each of the keys in these key:value pairs when I expand it further (ie wha is Target?, what is Subject/Object mean? what does State: Generated mean?,