What is a docker volume?

A Docker volume is defined as a directory on the host machine that is accessible to a container. Volumes are used to persist data generated by and used by Docker containers. This persistence is critical as containers are ephemeral by nature; when a container is removed, any data stored inside it is lost unless it has been saved in a volume. By storing data in volumes, you can share data between containers or recover it even after a container has been stopped or removed.

Volumes are managed by Docker and are stored outside the Union File System, which keeps them separate and allows for better performance and flexibility. This enables changes made in the volume to remain available even if a container is no longer running, allowing for safer data management and improved data sharing among multiple containers.