Containers vs VMs

Virtual Machines

• Each VM runs its own guest OS
• hypervisor - creates and runs VMs
• Each VM may be GBs in size
• Takes minutes to spin up
• Can consolidate apps onto a single piece of hardware
• Greater utilization on larger, faster servers

Containers

• Sit on top of a physical server and its host OS
• Each container shares the host OS kernel, and usually binaries and libraries too
• Containers are exceptionally "light"
  • Only MBs in size
  • Take seconds to spin up

Major Difference

Containers virtualize an OS so that multiple workloads can run on a single OS instance.

Virtual Machines virtualize hardware to run multiple OS instances