Configuration management:

Configuration management (CM) is the detailed recording and
updating of information that describes an enterprise's
computer systems and networks, including all hardware and
software components.

Change management:

In a computer system environment, change management refers
to a systematic approach to keeping track of the details of
the system (for example, what operating system release is
running on each computer and which fixes have been applied).

configuration management is nothing but maintaining the 
consistency of product's performance & its physical & 
functional attributes with it's requirement ,design and 
operational information throut it's life