Container

Low-weight alternatives to full-system virtualization provided by Virtual Machine.

• They provide OS virtualization above single shared kernel
  • Do not provide full-machine virtualization
  • Each VM has illusion of running on isolated machine
  • Each container has illusion of running on isolated OS
• Use OS constructs to provide sand boxes for execution
  • Ex: Linux cgroups, namespace, etc
• Can run on bare metal OS, or atop of OS running in VM
• OS containers: multiple applications run in same container
• Application containers: each application has its own container
  • Example: Docker, rkt

Virtual Machine vs. Container