a named specification that defines the data type and size for each field of an element
The name that appears in a start, end or empty tag. In the following example there are three elements but only two element types:student firstnameJo/firstname firstnameSephine/firstname /student
the first parameter in the element declaration, names the logical object(s) whose content will be defined in the content model. The name defined in the DTD becomes the generic identifier or tag name of the element when it is marked up in the document instance.