What is Docker? A Very Hot topic !

In a nutshell, Docker is a software containerization platform that provides abstraction of OS level virtualization.

In a high level, these containers contains the real OS,Software that you build, Dependencies to run the software, Environment Variables whatever you name it.

So what is the difference between Virtualization and containerization?

Virtualization	Containerization
Each VM runs its own  Operating System.	All Containers share same Kernel of Hosts
Host can be different than guest OS.	Host OS and Container OS has to be same.
Virtual machines take few minutes to come up/boot.	Docker Container take few mille  seconds to start/boot.
Only one VM can be started from one set of VMX and VMDK files.	Many Docker containers can be started from one Docker Image.
It is Hardware Based Virtualization, Where multiple guest OS share Host Resources.	It is OS based Virtualization, Multiple containers can run over same OS.
Heavy Weighted, Additional OS managed resources for each Guest.	Light weighted, Kind of App services sharing OS resources.
Slow Provisioning, Requires Guest initialization  plus OS startup time.	Real Time Provisioning, As simple as starting new application services.
Limited Performance, H/W Access through virtualization Layer.	Native Performance, Direct access to H/W resources.
Highly Secured: Fully Isolated hence More secured.	Less Secured:Process level isolation hence less secured.