Containers quite drastically vary from the highly visible and viable virtual machines (VMs). Virtual machines represent hardware virtualization whereas containers facilitate operating system-level virtualization. Some literature points out that virtual machines are system or OS containers whereas containers typically stand for application containers.

On the functional side, containers are like VMs, but there are dissimilar in many other ways. Like virtual machines, containers too share the various system resources such as processing, memory, storage, etc. The key difference is that all containers in a host machine share the same OS kernel of the host operating system.

Though there is heavy sharing, containers intrinsically maintain a high isolation by keeping applications, runtimes, and other associated services separated from each other using the recently incorporated kernel features such as namespaces and cgroups.

On the resource provisioning front, application containers can be realized in a few seconds, whereas virtual machines often take a few minutes. Containers also allow direct access to device drivers through the kernel and this makes I/O operations faster.

Workload migration to nearby or faraway cloud environments can be accelerated with the containerization capability. The tools and APIs provided by the Docker container technology are very powerful and more developer-friendly than those available with VMs.These APIs allow the management of containers to be integrated into a variety of automated systems for accelerated software engineering.