What is use of token tag in SOAP service?

Content

Hello everyone,

I am exploring  SOAP API documentation and when put it in SOAP UI their is one tag "<v1:Token>". I am unable to understand what is the use of this tag, even if I am assigning a value to this tag, the value is getting changed in response.

 

Thanks

Code Snippet

             <soapenv:Header>
      <v1:APIAccessRequestHeader>
<!-- I am talking about this tag -->
         <v1:Token></v1:Token>
      </v1:APIAccessRequestHeader>

      <v1:ClientInfoHeader>
         <v1:AppID>Basic Query</v1:AppID>
      </v1:ClientInfoHeader>

      <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" soapenv:mustUnderstand="1">
            <wsse:UsernameToken xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="UsernameToken-3902281">