Port forwarding between containers in Docker Compose file

I'm not too familiar with Docker or networking in general so I'm getting confused as to whats going on in my Docker Compose file below.

1. Would each of the services be available to the host machine at something like http://localhost:4200 ?

2. If the answer is yes above, how would I ensure that the correct ports are exposed between containers but not accessible to the host machine? Does it involve defining a network instead of relying on the default one?

version: '3' # specify docker-compose version

# Define the services/containers to be run
services:
  angular: # name of the first service
    build: ./Coding/DeepLearning/GardenApp/client-app-dev # specify the directory of the Dockerfile
    ports:
      - "4200:4200" 
    volumes:
      - ./Coding/DeepLearning/GardenApp/client-app:/usr/src/garden-app-dev

  express-ts: #name of the second service
    build: express-ts-server # specify the directory of the Dockerfile
    ports:
      - "3000:3000" 
    links:
      - database # link this service to the database service
    volumes:
      - ./Coding/DeepLearning/GardenApp/express-ts-server:/usr/src/express-ts-app

  database: # name of the third service
    image: mongo # specify image to build container from
    ports:
      - "27017:27017" 
    volumes: 
      - ./Coding/DeepLearning/GardenApp/database:/data/db

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