Docker is an open source project that provides the tools and ecosystem for developers to build and run applications inside containers.
Containerization is a method of virtualization. Virtualization is a method of running a virtual instance of a computer system inside a layer abstracted from the hardware. Virtualization allows you to run multiple operating systems on the same physical host machine.
From the view of an application running inside a virtualized system, it has no knowledge or interaction with the host machine, and may not even know that it is running in a virtual environment.
Containers are a type of virtual system. Each container is allocated a set amount of resources (CPU, RAM, storage). When a program is running inside a container, its processes and child processes can only manipulate the resources allocated to the container, and nothing more.
You can view a container as an isolated environment, or sandbox, on which to run your application...
