Copy files or directories between host and container filesystems.

# To copy a file or directory from the host to a container:
docker cp <path/to/file_or_directory_on_host> <container_name>:<path/to/file_or_directory_in_container>

# To copy a file or directory from a container to the host:
docker cp <container_name>:<path/to/file_or_directory_in_container> <path/to/file_or_directory_on_host>

# To copy a file or directory from the host to a container, following symlinks (copies the symlinked files directly, not the symlinks themselves):
docker cp --follow-link <path/to/symlink_on_host> <container_name>:<path/to/file_or_directory_in_container>