Who could explain what a container is? Like a Docker container, but not necessarily Docker. Google doesn't provide simple yet meaningful answer (or there is something wrong with me today). Any ideas?

My answer was something like 'unit of software that packages up code and all its dependencies so the application so it runs quickly and reliably from one computing environment to another. ... ", but it didn't satisfy my job interviewer at all

Docker is like convience food for cloud software.
You just open a tin can and your ready to eat. With docker you just run a command and within the minute you have running instance (for example) apache webserver, a database, and a load balancer. Without the need to installing and configuring it your self. So you've got more time developing your web app.

If you wand to learn more i highly recomend you this short tutorial on Katakoda. https://katacoda.com/courses/...

@heyheni yeah, containers give you a way to quickly run an app like aforementioned load balancer regardless of your environment, I guess. It sounds like my answer that didn't satisfy my job interviewer...

Like some say that container doesn't contain OS within it, that's why it is lighter. Others say that containers do have an OS which make possible to run environment of these containers separately from your host OS... wtf?!

@SavageRandy It's a half way house between a VM and just bundling the application - it still runs on the host OS and uses the underlying OS kernel, but (essentially) everything else built on the kernel is packaged up in the container.

This allows you to distribute packages with all the correct dependencies and system requirements in place, while being a much lighter alternative than bundling a full VM.

Here's a comprehensive explanation:

https://lmgtfy.com//...

Basically it's a small, lightweight, scalable VM

Finally I found a perfect explanation https://youtube.com/watch/...