At the below path of the DXA web application:
BinaryData/<PUBLICATION_ID>/??/System/Config
BinaryData/<PUBLICATION_ID>/??/System/mappings
BinaryData/<PUBLICATION_ID>/??/System/resources
I see various JSON file such as: _all.json, core.json, resources.json and few others.
Can you please help me understand the purpose of each of these JSON file? Also, which Template/Page/Component publishing results in these JSON files being created?
UPDATE 1:
Below JSON files I can see in broker DB:
The _all.json files hold references to other files, but can have additional data (like in the case of \system\cinfig_all.json)
BinaryData/PUBLICATION_ID/??/System/mappings
These files contain information which is needed by the framework to perform the semantic mapping when creating viewmodels.
BinaryData/PUBLICATION_ID/??/System/resources
These files contain your resources (ie. labels) which are defined in components which are linked to the Module Configuration component of your module
BinaryData/PUBLICATION_ID/??/System/Config
These files contain your configuration entries which are, similarly to the resource components, defined in components which are linked to the Module Configuration component of your module
Also, which Template/Page/Component publishing results in these JSON files being created ?
Strictly speaking, none :). That is, these files are created from the broker DB for a certain publication when you access one of its published pages. The mechanism how the content ends up in the broker is by publishing the _System\Publish Settings Page. Once you do that, you can obtain new values by using the /admin/refresh endpoint, because these files are not being recreated on every request.
Atila already explained the purpose of those JSON files pretty well.
Regarding where you find them in the Broker DB: these JSON files are published as Binaries (check your BINARY_VARIANTS table).
In the DXA Web Application, such items are called Static Content Items and they are cached on file system to improve performance.
