The Common Information Model (CIM) can be overwhelming to newcomers. There is a large amount of technical jargon within CIM, the IEC numbering and versioning system, and also within the governing bodies that oversee CIM such as the CIM Users Group. This page gives more context to some of this jargon and can be used as a reference as you navigate and learn CIM for yourself.
The CIM Users Group has a good summary of various CIM Standards and how they map to plain english descriptions. You can find it here.
Below is also a helpful illustration of this mapping.