Symantec  follows the  increasingly common architecture  of "console - server - client"  to satisfy  this  requirement.   A "console" is  a  management  piece  of software  used to define  how  servers and  clients  interact and  are  configured  and  may  be run  from various administrators  desktops.  "Servers"  are  responsible for updating and  controlling  access  to repositories  of information  (i.e., virus definitions) and  "clients"  actually  perform  the  work.   (Again,  as is  common in this  model, a  server  acts  as its own  client  so it  can  enjoy  a  superset  of the  features  available  to individual  clients.)     From an auditor's  point  of view it  will be  important to ensure  controls  are  in place  to allow  administrative  access  only to specific  people  and/or  workstations,  that appropriate  information  is  backed up on the  servers,  that clients  are  not  allowed  to ignore  information  from the  server  and/or  adminstrators  and  that administrators  are  provided  enough information  to identify  the  weaknesses  of their current deployment  and  find  out  what defensive actions the  system has  taken  in response  to specific perceived  threats.  
LiveUpdate is a program that connects to a server, downloads the latest definitions, and applies the definitions to the computer on which it is running. You can run LiveUpdate from Symantec System Center, or within Symantec AntiVirus. LiveUpdate can retrieve definitions files either from the Symantec server (which it does by default) or from an internal Web, FTP, or file server created with the LiveUpdate Administration Utility.

To run LiveUpdate on a primary server from the Symantec System Center Console

1. Right-click the primary server, and then click All Tasks > Symantec AntiVirus > Virus Definition Manager.
2. Click Configure.
3. Click Update Now.
   LiveUpdate now runs silently in the background on the primary server. If the VDTM is enabled, it will distribute virus definitions to any secondary servers and clients when LiveUpdate finishes.

To run LiveUpdate on managed clients from the Symantec System Center Console

1. Right-click a client or client group, and then click All Tasks > Symantec AntiVirus > Virus Definition Manager.
2. Click Configure.
3. Click Update Now.
   The affected clients try to obtain virus definitions from the parent server. After this attempt, the managed clients then run LiveUpdate.

To run LiveUpdate from the Symantec AntiVirus Corporate Edition interface

1. Start Symantec AntiVirus Corporate Edition.
2. Click LiveUpdate.
3. Follow the on-screen prompts to download the latest definitions. If the computer is a parent server and the VDTM is enabled, it will distribute virus definitions to any subordinate servers and clients when LiveUpdate finishes.

Source1: http://www.symantec.com/business/support/index?page=content&id=TECH100047
Source2:http://www.google.com/url?sa=t&rct=j&q=what+is+symantec+antivirus+corporate+edition&source/