Geek Out Time: Back to When I First Asked “What Is a Container?” -CGroups and Namespaces on Colab

I was reading this post the other day — Why I Ditched Docker for Podman (and You Should Too) — and it reminded me of the first time I learned about containers from this excellent YouTube talk nearly nine years ago. Time flies.

Although many developers and system admins use Docker every day, many still struggle to answer a deceptively simple question: What exactly is a container?

At its core, a “container” is made possible by just two Linux kernel features:

This geek out time walks through both concepts and includes a Google Colab cell you can run to observe them in action — even though Colab doesn’t allow changing kernel knobs. You’ll see real counters move, watch a memory-hungry process fail safely, and inspect namespace identities firsthand.

This is an excerpt — the full article continues on Medium.