Four common conflict minerals, clockwise from top left: coltan, cassiterite, gold ore, and wolframite. Conflict resources are natural resources extracted in a conflict zone and sold to perpetuate the fighting. There is both anecdotal and statistical evidence that belligerent accessibility to precious commodities can prolong conflicts (a resource curse).
The public server role is not a fixed server role, because the permissions can be changed. The public server role is granted VIEW ANY DATABASE permission and the CONNECT permission on the default endpoints (TSQL Local Machine, TSQL Named Pipes, TSQL Default TCP, TSQL Default VIA). Members of the securityadmin fixed server role can grant both server-level and database-level permissions.
Fixed-database roles are defined at the database level and exist in each database. Members of the db_owner database role can manage fixed-database role membership. There are also some special-purpose database roles in the msdb database. You can add any database account and other SQL Server roles into database-level roles. Each member of a fixed-database role can add other users to that same role.