Advantages of Linux Containers over Docker

I'd like to understand the differences between Linux Containers and Docker, especially what kind of advantages Containers have in comparison to Docker.

Docker is a specific implementation of Linux containers, or if you want to be more precise Docker is a distribution of tools that includes runc which is an implementation of Linux containers. Other implementations include rkt, LXC, LXD, and (I think) Snappy from Ubuntu.

StackExchange DevOps Q#396, answer score: 6