A Docker Container is a lightweight system that can be run on a Linux operating system or a virtual machine. It is a package of an application and related dependencies that can be run independently.
Since Docker Container is very lightweight, multiple containers can be run simultaneously on a single server or virtual machine.
With a Docker Container we can create an isolated system with restricted services and processes. A Container has private view of the operating system. It has its own process ID space, file system, and network interface.
Multiple Docker Containers can share same Kernel.