title: What is a passive web service?
body: <p>Our company is studying the adoption of a new SaaS, but we'll have to integrate some resources into ou current application.
  Talking to the SaaS company development support team they told us that the there is a webservice (SOAP) available but it is a 'passive web service', and that the connection to the software needs to be initiated to send or recieve datas.</p>
  
  <p>We have a very short time to take a decision, and the support team is not available on weekends, so I came here to stackoverflow... and would like to know more about it, because I googled and coudn't find anything about the subject</p>