The original Linux container is Linux Containers, commonly known as LXC. LXC is a Linux operating system-level virtualization method for running multiple isolated Linux systems on a single host. Namespaces and cgroups features make LXC possible.
Containers decouple applications from operating systems, which means that users can have a clean and minimal Linux operating system and run everything else in one or more isolated container. (source)
Initially Fedora will be targeting the [www.docker.com Docker] container implementation but there are many and others will likely be incorporated in the future.