CMM - Capability Maturity Model

CMMI - Capability Maturity Model Integration

CMM describes about the software engineering alone where as 
CMMI describes both software and system engineering. CMMI 
also incorporates the Integrated Procees and Product 
Development and the supplier sourcing.

CMM - One Model
CMMI - Integrating many different models into one Frame work

Verygood answer Padmaja
but still i want to add some thing 

ISO 9000 	??Quality Management Standards?
This means what the organization does to fulfil:
  The customer's quality requirements, and
  applicable regulatory requirements, while aiming to
  enhance customer satisfaction, and 
  achieve continual improvement of its performance in
  pursuit of these objectives. 
CMM have 18 KPA,s(key process areas)
CMMI have 24 KPA's

rajendra_penumalli@yahoo.com

CMM is a model of process maturity 4 s/w development-an 
evolutionary model of d process of a company's abilities of 
develop s/w.