Why Docker Exists — The Problem Nobody Explains | Docker #1

Most Docker tutorials start with commands. This one starts with the problem — why "it works on my machine" keeps happening, and what people tried before Docker existed. If you've heard of Docker but never understood what a container actually is, this video is for you. No commands, no setup, no prior experience needed. We build the idea from scratch: the real problem developers kept hitting, the solutions that came before (install guides, virtual machines, automation scripts) and why each one fell short, and then what Docker actually does differently under the hood. This is Part 1 of a 3-part Docker series. Part 2 is fully hands-on. What you'll learn Why software breaks on a different machine even when the code is identical What people tried before Docker — and the new problems each attempt created What an operating system actually does: kernel vs userspace, explained simply How a container differs from a virtual machine, and why it's so much lighter How namespaces and cgroups create the illusion that a container is alone on the machine Why Docker containers are Linux containers — and what that means on Windows and Mac Got a question or something that didn't click? Drop it in the comments — I read all of them and often turn them into future videos. If this helped, subscribe for the rest of the series.