What is the Docker File System?
A Docker container executes the software stack specified in a Docker image. Images are built up of read-only layers that operate on the Union File System. When we start a new container, Docker adds a read-write layer on top of the image layers, allowing the container to function like a conventional Linux file system. So, each file modification within the container generates a functioning copy in the read-write layer. However, when the container is stopped or removed, the read-write layer disappears.
What Is Docker Volume?
Docker containers enable apps to execute in an isolated environment. All modifications made inside the container are lost by default when it ends. Docker volumes and bind mounts can be useful for storing data in between runs. One way to store data outside of containers is with volumes. All volumes are kept in a specific directory on your host, typically /var/lib/docker/volumes for Linux systems, and are controlled by Docker.