Server-Level Roles
Fixed server roles are server-wide in their scope. Each member of a fixed server role can add other logins to that same role.
The fixed server roles are:
See Also
Concepts
Permissions of Fixed Server Roles
Other Resources
sp_helpsrvrole (Transact-SQL)
sp_helpsrvrolemember (Transact-SQL)
sp_srvrolepermission (Transact-SQL)