Docker Images are the base for
and are similar to
files. They can be for example the image of your app and contain everything needed to run the application.
These images can be local or in repositories (and marked with an tag)
To create images, you must create a
with some docker commands to specify how that image will be created, for example to setup the environment and a BaseImage.
Docker Swarm is available only for version "3"
When you run an image with you are starting a Container, so container is the runtime instance of an
, and consists of the image, an execution environment and a standart set of instructions.
With Docker you can increase resource and capacities by creating a
, which are simply several machines (virtual or physical) running a Docker and joined to a cluster.
Swarms have the
, which can issue docker commands normally, and the
which are only there to provide capacity.