Questions regarding Sid, Sidhistory, trust and resource sharing

Dear Support,

Hope you guys are doing good.

Please excuse me for little understanding. I have few questions that needs to be answered and explained.

Q1: In case of forest trust and external trust, Sid and Sihistory of which groups (Domain Local, Global and Universal) will cross trust while accessing resources in different forest?

Q2: What is the difference between forest trust and external trust in terms of Sid, Sidhistory and group scope (Domain Local, Global and Universal) while accessing resources ?

Q3: After authenticated by home domain of user, if user wants to access files/folders in resource domain(different forest), does resource domain also have to authenticate user before granting access? OR Does resource domain only play role in authorization process? Could you please explain the workflow in brief for this scenario?

Thank you!