Where is my image, container stored?

Docker Desktop
1

I follow the link https://docs.docker.com/get-started/docker-concepts/building-images/multi-stage-builds/ and I can successfully run the container and image spring-helloworld, but where is the image, container really in?

I type all my command in Ubuntu terminal, and in docker.desktop, container, inspect, the hostsPath is “”/var/lib/docker/containers/dd739300dd52be7c8f410f228a07bfa92fdd5b822e1c273b120ec9b8077b2765/hosts", but no /var/lib/docker in my Ubuntu, even sudo to root by
sudo su -
the result is

cd /var/lib/docker/
-bash: cd: /var/lib/docker/: No such file or directory

if I type
docker exec crazy_volhard /bin/bash

it returns
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

(crazy_volhard is the container name for image spring-helloworld.)

And I google and some said in docker desktop, it create docker in a VM and the image is in the VM, not in the host.
But in my whole process, I use terminal to run
docker build -t spring-helloworld .

this also mean I build the docker image using docker desktop, not docker engine?

And If I type
docker context ls

it returns

NAME              DESCRIPTION                               DOCKER ENDPOINT                                ERROR
default           Current DOCKER_HOST based configuration   unix:///var/run/docker.sock                    
desktop-linux *   Docker Desktop                            unix:///home/userA/.docker/desktop/docker.sock
2

Inside the virtual machine of Docker Desktop, but you should not even need to know that normally. Everything can be done with commands and doing anything in the Docker data root is also dangerous.

The client doesn’t have to be on the same machine as the daemon. With Docker Desktop, you have the daemon in the VM and a client on the host. Communication with the daemon is done by using a special socket and all requests are forwarded to the daemon in the VM.

I wrote a bout “Where does Docker store data?” and different Docker variants and how they work: Which Docker variant am I using and where is the daemon running? - DEV Community