The significance of the EHR, and its position as THE repository of observations made during care received by patients, is that it IS the foundationstone of healthcare and its supporting information domain. The recent Institute of Medicine 2001 report (Reference A12) clearly recognized that importance and criticized the slowness in progressing towards the vision of the 1991 report (Reference A3). The EHR is the keystone to the resource management functions that are the present focus of the 1996 HIPAA legislation and which complement, but are second in priority to, the EHR as THE patient care record for the future. It is the purpose of this site to explore and point out the various dimensions that must be recognized and dealt with from an “Enterprise View” and “Life Cycle Principles” in order to achieve the vision of the 1991 IOM report. Shown graphically, the importance of the EHR  in drawing on other information sub-domains and acting as the central source of information about health care is  depicted in the following figure: