Docker vs Virtualization

[linux_tux]

I am a newbie in linux. i am using a laptop installed with windows7 (licensed) which i cannot delete. I wanted to install Centos which i got from a magazine "linux for you" virtually. Read documentation about virtualization. One of my friend told me about something named docker. Wanted to know what is hypervisor. Is docker the same as hypervisor?

[rameez]

No, It's not.

Unlike other types of virtualization, containers are much light weight and has less overhead. Hypervisor based virtualization technologies require a virtual hardware that needs to be created, on top of which an operating system with its own kernel and drivers are installed. So technically hypervisor based stuff is a full isolation, and to the base operating system, the guest system looks as an independent host, which has no relation to itself.

Containers share the same kernel which the base operating system is using. This is the main plus point of a container based virtualization as well as a limiting point. Its a limiting point because, it cannot run any other operating system like windows on it(Simply because a Linux kernel can only run a Linux distribution..as simple as that.)

The main advantage of using docker is the "shipping" part. When i say shipping, you are shipping an entire container and your applications inside the container with all its dependencies. This makes running that containerized applications anywhere so easy and gives you the guarantee that your application will run as expected. Portability is the main thing that docker aims at.