Yep, jails, containers, solaris zones all the way back to IBM mainframes have been similar core technologies. Docker it self isn't containerization, Docker builds on Linux containers but adds a layer to dramatically simplify the build, distribution and execution of containers and that's what makes it game changing.

docker run gtihub.com/some/project

That command will clone, build and execute a container based on the contents of a repository by simply dropping a Dockerfile in the root of the project. That's a fundamentally different level of usage beyond any existing container technology.