Question

Someone once observed that "the difference between roles and groups is that a user be able to shift into and out of roles, whereas that user has a group identity (or identities) that are fixed throughout session."

a. think a system such as a Berkeley-based UNIX system, in that users have secondary group identities that remain fixed during their login sessions. What is compensation of roles with the same administrative functions as the groups?

b. think a system such as a System V-based UNIX system, in that a procedure can have exactly one group identity. To change groups, users have to execute newgrp command. Do these groups be different from roles? Why or why not?