The
web.xml file is a
deployment descriptor. It defines how your web components (
servlets, JSPs, HTML files, etc) are organized to form a coherent web application. All Servlet 2.3 compliant webapps must have a web.xml file.
The server.xml is a configuration file for Apache Tomcat and describes how your web applications (or
contexts) are deployed onto Tomcat. This is not a J2EE-specific feature. For another web server, for example, (say JRun) the equivalent file is the local.properties file.
-anthony