How to implement something to differentiate nodes? I wonder how I could implement something in my Drupal site where nodes can be different and managed separately.

For example, in my site I want to add to nodes as shops, and every vendor must manage his/her shop, post news, add images, etc.

Any suggestions
You could, for sure, use the Group module for this. Group allows for creating arbitrary collections of your content and users on your site, and grant access control permissions on those collections. It is available as of D7, and has a D8 version also. It is designed to be an alternative to Organic Groups. The Group module creates groups as entities, making them fully fieldable, extensible and exportable.

For more details about the various roles and permissions, refer to my answer to "What are the various roles supported by the Group module?".

Resources


Community documentation for the Group module.
Video tutorial "How to use the Group module in Drupal 8 to manage editorial access control to different areas of a web site".