anchor.diff:  You used Docker Machine already during the attendee setup. We won't need it too much further on. But if you need to create hosts, it's a very handy tool to know about. From now on we're mostly going to use the docker client.
   Find out more about the details at the link:https://docs.docker.com/machine/[Official Docker Machine Website]
   
  -Check if docker machine is working with
  +Check if docker machine is working using the following command:
   
   [source, text]
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positive.code: 
  One of the reasons Docker is so lightweight is because of these layers. When you change a Docker image—for example, update an application to a new version— a new layer gets built. Thus, rather than replacing the whole image or entirely rebuilding, as you may do with a virtual machine, only that layer is added or updated. Now you don't need to distribute a whole new image, just the update, making distributing Docker images faster and simpler.
  
  Every image starts from a base image, for example ubuntu, a base Ubuntu image, or fedora, a base Fedora image. You can also use images of your own as the basis for a new image, for example if you have a base Apache image you could use this as the base of all your web application images.
  
  _Note: Docker usually gets these base images from Docker Hub._
  
  Docker images are then built from these base images using a simple, descriptive set of steps we call instructions. Each instruction creates a new layer in our image. Instructions include actions like:
  
  
negative.code: ----
  
  ### Docker Client
  
  The client communicates with the demon process on your host and let's you work with images and containers.
  
  Check if your client is working using the following command:
  
  [source, text]
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