[ryanmcbride]

The joke that I think actually explains it pretty well is that it eliminates the "well it works on _my_ machine" problem, by not just shipping the code, but shipping the machine.

[0xEFF]

It's also a great way to make sure your build artifacts are owned by root so you don't accidentally delete them.

[MaxBarraclough]

*shipping the userland

It's not the equivalent of handing over a VM image. You're still open to unintended sensitivity to kernel versions, for instance.

[ryanmcbride]

I know that this joke isn't exactly what's happening. I just feel like it's a good way to explain the _idea_ of Docker to people who have no idea what it is.