title: Docker- what real value does it bring for our team?
body: <p>I am very very new to Docker. Our team has had a very nice deployment line up where We have different CI engines for different projects including Jenkis and TeamCity. </p>
  
  <p>Developers usually check-in and CI takes over, deploys and its perfectly ready for test team to test. I always thought this to be a perfect model. Of course, some parts and our implementation have their flaws but it worked very well for what we wanted.</p>
  
  <p>Now, our Dev-Ops is introducing Docker where test teams get a Docker Image from Docker Registry Everytime we run a build from teamcity. While it sounds really really fancy I am still failing to understand the benefit of it.</p>
  
  <p>After my research, my conclusion was that Dockers can be a good light weight replacements for VM. BUT that is ONLY IF you are using any VMs? We are not using any VMS? I just do not understand what is the real value here? Also, while searching I found a relatively good link on Docker:</p>
  
  <p><a href="https://www.ctl.io/developers/blog/post/what-is-docker-and-when-to-use-it/" rel="nofollow noreferrer">https://www.ctl.io/developers/blog/post/what-is-docker-and-when-to-use-it/</a></p>
  
  <p>Where they discuss when you should use Docker and one of the point says that:</p>
  
  <p>Use Docker whenever your app needs to go through multiple phases of development (dev/test/qa/prod, try Drone or Shippable, both do Docker CI/CD)</p>
  
  <p>Ok. Howeve rthey do not further elaborate on why is docker useful when my app has to go through multiple phases?</p>
  
  <p>And how it is exptremely helpful over regular Dev/Test set up when the existing set up is already working smooth?</p>