Docker-compose: volumes:

Docker compose file: docker-compose.yml (examples)

volumes: 

Examples

https://docs.docker.com/compose/compose-file/compose-file-v3/#volume-configuration-reference

version: "3.9"

services:
  db:
    image: db
    volumes:
      - my-data-volume:/var/lib/db
  backup:
    image: backup-service
    volumes:
      - my-data-volume:/var/lib/backup/data

volumes:
  my-data-volume:

https://docs.docker.com/compose/compose-file/#volumes#driver_opts

volumes:
 example:
   driver_opts:
     type: "nfs"
     o: "addr=10.40.0.199,nolock,soft,rw"
     device: ":/docker/example"

https://docs.docker.com/compose/compose-file/#volumes#external
If set to true, specifies that this volume has been created outside of Compose.

volumes:
 data:
   external: true

https://docs.docker.com/compose/compose-file/#volumes#driver_opts

volumes:
  grafana_storage:
         driver: local

See also

• docker-compose, docker-compose.yml: [services | volumes | networks | up | down | restart | logs | create | changelog | version | secrets | config | -v | -h | exec], docker-compose pull, Environment:, Docker-compose.yml examples, .env, release notes, expose:, docker-compose --env-file, services.deploy.resources
• Docker Volumes: docker volume ls, docker volume create, docker volume inspect, docker volumes prune, docker volume create, docker volume rm, docker system df, mounts, --volumes-from

https://docs.docker.com/compose/compose-file/#volumes