Using XML with Legacy Business Applications

Simple and Complex

One of the things I found somewhat confusing when first learning schema language is how it uses the terms “simple” and “complex.” These are used in two different contexts.

In the first context, the terms “simple” and “complex” describe the type of content an Element may have, or its content model. In the most general terms, an Element may be declared in schema language with one of two content models.

• Simple content: The Element has no child Elements.

• Complex content: The Element may have child Elements.

These types of content are represented using the schema language Elements xs:simpleContent and xs:complexContent, respectively. In addition to simple and complex, there are various types of content models for complex content. ...