You can't use the .NET Framework effectively unless you're familiar with XML. That's true even if you're only working with desktop applications, but if you want to write XML Web Services and other distributed applications, XML knowledge is even more important. The .NET Framework uses XML for many purposes itself, but it also makes it very easy for you to use XML in your own applications.
The FCL's support for XML is mainly contained in the System.Xml namespace. This namespace contains objects to parse, validate, and manipulate XML. You can read and write XML, use XPath to navigate through an XML document, or check to see whether a particular document is valid XML by using the objects in this namespace.
XML Basics In this chapter, I assume that you're already familiar with the basics of XML, such as elements and attributes. If you need a refresher course on XML Basics, refer to Appendix B, "XML Standards and Syntax."
As you're learning about XML, you'll become familiar with some other standards as well. These include the XPath query language and the XSD schema language. In this chapter, you'll see how these other standards are integrated into the .NET Framework's XML support.