Excellent description of CI, SDM Package related to Software Update, DCM, NAP etc from Steve Rachui.
First, some definitions.
CI – A CI is short for Configuration Item. A configuration item generically is a discrete unit of configuration to assess for compliance. They can contain one or more elements and their validation criteria, and they typically define a unit of configuration you want to monitor at the level of independent change.
SDM Package – A SDM package is short for Service Definition Model. You may also hear the SDM Package described as using the SML – service modeling language. SDM Packages link together with CI’s and further describe how to effect whatever configuration it is that we wish to evaluate or implement.