Public administration is a feature of all nations, whatever their system of government. Within nations public administration is practiced at the central, intermediate, and local levels. Indeed, the relationships between different levels of government within a single nation constitute a growing problem of public administration.
In most of the world the establishment of highly trained administrative, executive, or directive classes has made public administration a distinct profession. The body of public administrators is usually called the civil service. In the United States and a few other countries, the elitist class connotation traditionally attached to the civil service has been either consciously abandoned or avoided, with the result that professional recognition has come slowly and only partially.