I am slightly embarrassed to say, even when I see all these folks say amazing things about how Docker made their lives easier, I still can't wrap my head around exactly what it is. (This when I KNOW I want jail-like isolation between many of my rails apps on one server)

Is it like a jail in BSD? Ok but then what are the chef-like recipes for? (the docker recipe-like stuff is leading me to think that)... I get the benefits of shipping containers, but what does this do for Quotas? for differing paths? How does it solve init.d vs Upstart vs launchd issues?

Also, on index.docker.io, how do I view these recipes? What do they look like?

Hopefully there's a youtube video out there where a speaker gets a little less abstract and more detailed about where these pieces fit in, actually looking at an SSH prompt on a server.