It is useful to think about computer security in relationship to physical office security. A computer password can be thought of as a lock and key.
The first level of security, the windows log-on, is like the key to the office door. If you don’t have that key you can’t get into anything.
The second level is application passwords. These are like keys to the filing cabinets. This key allows you to get into the charts. However there is still a locked drawer in the Dr.’s office
The third level of security is like the key to the locked drawer where the cash and checkbook is kept.