Collaboration meaning: I'd like to know more about

I'd like to know more about the advantages and disadvantages of forking a github project vs. creating a branch of a github project. Forking makes my version of the project more isolated from the In github, I often see these terms and in many cases they are used interchangeably. Can someone please explain the difference between a contributor and a collaborator? The collaboration branch is different also from the others for being able to call ADF pipelines from logic apps or anything else external to ADF (after using the publish button). When creating a Collaboration Diagram in Doxygen that specifies the connections between Doxygen groups, what is the meaning of a purple dashed line without an arrow?