CDA (Clinical Document Architecture): Released in 1999. Clinical summary documents are based on this architecture.
CCR (Continuity of Care Record): Released in 2004. Patient summary info.
CCD (Continuity of Care Document): Released in 2007. Interoperability solution resulted as a combination of CDA and CCR.
CCDA (Consolidated Clinical Document Arhitecture): Released in 2011. Latest compromise of CCD document templates.
referenced from http://www.integrationrequired.com