A server role is a set of software programs that, when they are installed and properly configured, lets a computer perform a specific function for multiple users or other computers within a network. Generally, roles share the following characteristics.
Server Manager
They maintain a collection of files that we can download
CAS
Print Services
CAS and Mailbox
The use of the Server 2k3 after migration of Migration of Active Directory 2003 to 2008 is to transfer fsmo roles and to demote windows.
The server supplies the information or access point and the peer is the computer requesting the information
cas and mailbox
It depends on the computers hardware.
in Active Directory server roles, computers that function as servers within a domain can have one of two roles: member server or domain controller. A member server is a computer that runs an operating system in the Windows 2000 Server family or the Windows Server 2003 family, belongs to a domain, and is not a domain controller. Member servers typically function as the following types of servers: file servers, application servers, database servers, Web servers, certificate servers, firewalls and remote-access servers.
Documentations/policies, ip structures/server roles, cabling/topology, server settings and applications configuration.
Mailbox role