title: Docker --tag vs --name clarification
body: <p>I'm pretty new to docker and I'm a bit puzzled by the difference between tagging (--tag) an image and assigning it a name (--name).
  For example, I can see that if I build my custom image out of a Docker file, I can tag it with a name:</p>
  
  <pre><code>sudo docker build --tag=tomcat-admin .
  sudo docker run -it tomcat-admin
  </code></pre>
  
  <p>Passing the name to docker inspect produces a result:</p>
  
  <pre><code>docker inspect tomcat-admin
  </code></pre>
  
  <p>However it doesn't contain the same attributes of a "named" image:</p>
  
  <pre><code>docker inspect --format '{{ .NetworkSettings.IPAddress }}' tomcat-admin
  
  Template parsing error: template: :1:19: executing "" at &lt;.NetworkSettings.IPA...&gt;: map has no entry for key "NetworkSettings
  </code></pre>
  
  <p>"</p>
  
  <p>Somebody to shed some light on it?
  Thanks!</p>