The framework consists of the following core XML elements: Envelope, Header, Body, and Fault, all of which are from the http://schemas.xmlsoap.org/soap/envelope/ namespace in SOAP 1.1. I've provided the full XML Schema definition for SOAP 1.1 in the following code for your reference as you read through the remainder of this section. Personally, I find it helpful to inspect the schema whenever familiarizing myself with XML constructs.SOAP UI is a tool use to test whether SOAP is sending and receiving the messages properly as part of Unit testing in IT projects.