ITNinja

Sometimes referred to collectively as "Deployment System", there are inconsistent references to this which makes it very confusing to determine just what is being identified.
Deployment Server is what was once referred to as eXpress (and still is in some places). It is the 32-bit Windows application which is installed with Altiris_DeploymentServer_6_5_HF2_Full.exe. It provides the fat client console as well as a web console (which looks identical to interface provided by Deployment Solution (detailed below).
Deployment Solution is the Notification Server add-in which provides the "deployment" tab in the Notification Server web console. It is installed with Altiris_DeploymentSolution_6_5.exe. In fact, if you install Deployment Solution first- you can find the setup files for Deployment Server in the NSCAP share which you may run manually if needed.
Deployment Server does not require Notification Server-- if you are told you need to have Notification Server installed beforehand, you are installing Deployment Solution (not Server). Deployment Server can stand alone. Deployment Solution requires both Notification Server and Deployment Server.
Clear as mud?