Configuration data are made accessible to the Zend_Config constructor through an associative array, which may be multidimensional, in order to support organizing the data from general to specific. Concrete adapter classes function to adapt configuration data from storage to produce the associative array for the Zend_Config constructor. User scripts may provide such arrays directly to the Zend_Config constructor, without using an adapter class, since it may be appropriate to do so in certain situations.

Zend_Config implements the Countable and Iterator interfaces in order to facilitate simple access to configuration data. Thus, one may use the count() function and PHP constructs such as foreach upon Zend_Config objects.

By default, configuration data made available through Zend_Config are read-only, and an assignment (e.g., $config->database->host = 'example.com') results in a thrown exception. This default behavior may be overridden through the constructor, however, to allow modification of data values.

Adapter classes inherit from the Zend_Config class since they utilize its functionality.

The Zend_Config family of classes enables configuration data to be organized into sections. Zend_Config adapter objects may be loaded with a single specified section, multiple specified sections, or all sections (if none are specified).

Zend_Config adapter classes support a single inheritance model that enables configuration data to be inherited from one section of configuration data into another. This is provided in order to reduce or eliminate the need for duplicating configuration data for different purposes. An inheriting section may also override the values that it inherits through its parent section. Like PHP class inheritance, a section may inherit from a parent section, which may inherit from a grandparent section, and so on, but multiple inheritance (i.e., section C inheriting directly from parent sections A and B) is not supported.