I'd recommend you review the documentation (via the below link) for details on each of the various components.
http://www.symantec.com/docs/DOC5560
For a brief overview though:
- Framework exists on both the server and client side. On the server, it installs as the SEE Manager Computer/Console and is required to manage everthing. On the client side, it acts as the agent and is the bit that communictaes with the server (see point 2 below) for policy updates and such.
- The Management Server is pretty self explanatory, and is required for management as well.
- Helpdesk is only required when using Full Disk encryption. It's installed on the Manager Computer/Console and provides helpdesk options for getting users users who have forgotten their passwords logged on via a One Time Password.
- Full Disk edition provides disk encryption. It must be installed to the Manager Computer/Console first to manage/produce the client installer.
- RS provides encryption for removable storage devices like CD's, USB drives and the like. Again, this needs to be installed on the Manager Computer/Console to manage and produce the client component.
- The OTP key changer is only required if you need to change the Management Password, or if you lose the DB and don't have a backup.