What are extended in xml schema from dtd?

In XML Schema (XSD), several features are extended compared to Document Type Definitions (DTD), including data types, namespaces, and more complex structures. XML Schema allows for the definition of various built-in data types (such as integers, dates, and strings) and custom types, providing greater precision in data validation. Additionally, XSD supports namespaces, enabling the use of elements from different XML vocabularies without conflict. This enhances modularity and reusability compared to the simpler structure of DTDs.