Difference between 'image' and 'build' within docker compose

Question

Please help me understand the difference between \'image\' and \'build\' within docker compose

Answer 1

build: expects dockerfile path as an argument, it will build an image first and then use the image to create a container.

image: expects existing image name as argument , it will launch container using this image.

Example:docker-compose.yaml

version: '3'
services:
  service1:
    build: .
    ports:
      - "5000:5000"
  service2:
    image: "redis:alpine"

service1 will build an image first based on Dockerfile of current path and run container based on this image.

service2 will download "redis:alpine" image from docker hub and run container on downloaded image.