Containers is a light weight virtualization which is also known as Operating system level virtualization. As a definition its a middle-ware and echo system that allows sharing the Operating system between multiple instances that are called containers.
Each container is separated from other containers and could have a different Linux flavor than other container and the base operating system.
Although docker is an implementation of the idea but it have been greatly adapted through all the community the open source and the great cloud providers e.g. Amazon, Microsoft and Google.
Moreover, at DockerCon 2014, Google’s Eric Brewer announced that Google would be supporting Docker as its primary internal container format.
Also, Microsoft announced that windows server 2016 will support docker containers in the docker standard image format.
There are various contributions to the container idea by the open source community and even the multinational companies.