Will there be data loss inside a Docker container when it is stopped?

Data inside a Docker container by default is stored in the container's filesystem, which is temporary. When the container is stopped or removed, this data will be lost.

To prevent data loss, the following are used:

• Volumes — special storage areas that exist independently of the container's lifecycle.
• Bind mounts — mounting directories from the host into the container.

Example of using a volume:

docker run -v mydata:/app/data myimage

Thus, data is stored outside the container and is not lost when it is stopped or removed.