Networks configuration for docker-compose.yml files for docker

  docker, question

Example of official docker-compose.yml file:https://docs.docker.com/compo …

In the official example, networks looks like this:

networks:
 frontend:
 backend:

Question:
networksThe value offrontendbackendWhat does it mean? Other examples cited by Baidu are written in a variety of other ways.

Frontend, backend are custom network that need to be created manually (for example:docker network create frontend)

This way, you can declare and use it in the compose file