name sent by the customer support application will not match the name used by the order management module. So standardization of information is required to ensure that an application and the information base are more scalable. For the above example, the standardization of information is achieved by defin- ing the number of fields to be used in defining a customer name. For a customer entity, there will be multiple attributes that can be used to define the entity. The number of fields to be used for each of these attributes, if defined, will improve Fundamentals of EMS, NMS and OSS/BSS interoperability between modules that work on the customer entity. So if a cus- tomer name is defined to have first name, middle name, and last name in all appli- cations, then applications that need to exchange information relating to customer name will be able to interoperate without using an adapter. The SID model was developed by TeleManagement Forum and the CIM was developed by Distributed Management Task Force. These models are widely adopted in current industry. While SID is mainly for telecom solutions, CIM is mostly used in enterprise solutions. With convergence, there was a need for a com- mon model in telecom and enterprise industry. This led to the development of standards to map SID and CIM as a joint venture of TMF and DMTF. GB932 and GB933 from TMF and DSP2004 and DSP2009 are some of the documents that detail the alignment between the models. This chapter explains the fundamentals of SID and CIM SO that the reader can understand how an information model can be used in developing appli- cations that are compliant to information standards. The common terminol- logies used in the standard documents on information models is discussed in this chapter so that the reader can easily interpret information while reading a SID or CIM document for developing a specific application. The choice of what information model needs to be used in developing an application is driven by business requirements. SID is a part of the NGOSS fram