Hello Aishwarya,
Generally speaking, the plain lines represent the direct effective relationship, so the match links between the masters and golden.
Dotted lines can mean two things.
Either a relationship issued from transitive scoring:
Or a proposed suggestion:
In either case, if you hover your mouse on the dotted line, it should le you know (as per in my screenshots).
Regarding the second part of your question, I can't say for sure without seeing the use case, but I would say that those masters may have been regrouped by transitive scoring only, hence all those dotted lines.
Aishwarya Walia
Can some explain what do the dotted lines and bold lines in Explain Record graph mean? And when is a master record shown connected to all other master records with dotted lines