These roles are defined by Role Scoper (and possibly other plugins) for your use in designating content-specific access. Although the default capabilities are ideal for most installations, you may modify them at your discretion.
Since Role Scoper role definitions pertain to a particular object type, available capabilities are defined by the provider of that object type. Wordress core or plugins can add or revise default role definitions based on available capabilities.
Wordpress Role assignments function as a default which may be supplemented or overriden by blog-wide or content-specific assignment of these RS Roles.
These WordPress role definitions may be modified via the Role Manager plugin.
To understand how your WordPress roles relate to type-specific RS Roles, see WP/RS Role Equivalence.