Basics

Apache Axis is an Open Source SOAP server and client.. But Axis isn't just a SOAP engine -- it also includes:

a simple stand-alone server,
a server which plugs into servlet engines such as Tomcat,
extensive support for the Web Service Description Language (WSDL),
emitter tooling that generates Java classes from WSDL.
some sample programs, and
a tool for monitoring TCP/IP packets.

Axis handles the magic of converting Java objects to SOAP data when it sends it over the wire or receives results. SOAP Faults are sent by the server when something goes wrong; Axis converts these to Java exceptions.