for

• developing applications
• shipping applications
• running applications
• separate applications from infrastructure
• allows you deliver software quickly
• manage your infrastructure same was you manage apps
• has methodologies
  • reduce delay between writing code and running it in production

Dockerfiles

• builds an image file
• Dockerfile reference | Docker Documentation
• commands
  • build from Dockerfile and a context
    • context:
      • set of files at a specified location PATH or URL
      • process recursively
  • docker build
• .dockerignore file
• -f flag
  • points to a Dockerfile anywhere in the file system
• -t flag
  • tag an image with a name *

Other notes linking here:

Tech stuff