What is the difference between the default run_list and '_default' environment run_list in chef? -

I'm a bit confused about how to use the Environmentalist in Chief. As you can see the following role. In Jason Env_run_lists, you have _default and then we already have default run_list what's the difference? And what will run every time the run_list environment runs? "Chef :: roll", "[ap: :: copy_dev_configuration]"]}, "webserver", "default_attributes": {}, "json_class" Antivirus "run_list": ["role [base]", "recipe [apache]"], "description": "web server's role", "chef_type": "role", "override_editribute": {}}

  
 
 
 I agree that this is quite confusing, especially because it seems wrong in practice. Seeing the source can see.  
 By reading, we can see that when  role  is created the object then it creates the keys of the  run_list  property of the _default environment Again, and then merged into the hash with the contents of  env_run_lists  attribute (written at value for _default key).  
 This is what NS in practice is that if you specify the  run_list  attribute, then you can add the _default environment to the  env_run_list  attribute < Em> not  if you choose to include the _default environment in the  env_run_list  attribute, then it will overwrite anything defined in the  run_list  attribute.  
 Another obvious point indicates that if your node is not part of any environment defined in the role (_default or otherwise).