Docker –version         gives the version of docker that’s being used Docker pull                 to pull an image from the registry Docker run <image>  to create a container Docker ps                    list of running containers Docker ps –a               shows all the running and exited containers Docker stop                stop a running container gracefully Docker kill                  stops a running container abruptly Docker commit           creates a new image of an edited container Docker push                used to push an image

CMD is an instruction given in the dockerfile which is executed in the container when the image is run. When two CMD instructions are given in the dockerfile, the latest one is executed. Entrypoint is similar to CMD except that when more instructions are given all are appended.    Dockerfile should specify at least any one of the CMD or Entrypoint commands.

Dockerfile is a simple text file which is a collection of commands and instructions that are used to build a docker image. The Docker build command is used to build docker images using the instructions mentioned in the dockerfile.

Docker exec command is used to access the contents of a container and runs the commands inside the container. Docker attach command is used to attach our terminal to a running container to view it’s working.

Docker stop stops the running container by gracefully stopping step by step whereas docker kill abruptly stop a running container.

Docker pause is used to pause or suspend a running container or containers depending on the input. This puts a pause on all running operation happening at that instance. Docker unpause simply resumes the operations in the container.

A docker consists of      Docker client which puts up the request for the client in order to perform a request.      Docker host which contains the docker daemon. The requests which are put up by the client are processed here i.e containers are created and images are pulled from docker registry/hub. Docker registry is the place where the different apps images are stored. These images are pulled to the host where they are processed by creating a container.