Is it necessary to use networks when using links?

Hello,
In a YAML file, two containers are defined, which are connected by using the links option:

services:
    nodejs:
      container_name: Node
      build:
         context: .
         dockerfile: Dockerfile
      volumes:
        - /var/www/html:/usr/share/nginx/html/
      expose:
        - "3000"
    nginx:
      image: nginx:latest
      container_name: Nginx
      ports:
        - '80:80'
      volumes:
        - ./default.conf:/etc/nginx/conf.d/default.conf
        - ./www:/usr/share/nginx/html
      depends_on:
        - nodejs
      links:
        - nodejs

Is it necessary to use the networks option to connect these two containers? I am asking this question because I saw these two options together in a YAML file.

Cheers.