# What Docker Compose Is For — Docker Compose

Source: https://www.skillbyai.com/en/docker-compose/i-why

> Multi-container apps on one machine.

## Declarative local environments

**Docker Compose** defines an application made of several containers (a web front end, an API, a database, a cache, a worker) in one YAML file and manages them together: build images, create networks and volumes, start containers in dependency order, show combined logs, and tear everything down. It is ideal for **local development**, integration tests in CI, demos and small single-host deployments. For multi-machine production with self-healing and autoscaling, orchestrators such as Kubernetes are the usual next step.

## One file, one command, many containers

Compose describes a multi-container application in YAML and runs it with a single command.

![Three ideas: why Compose, the file, the lifecycle.](assets/figures/docker-compose/section-1-map.svg) — Figure 1.1 — Purpose, file and lifecycle.

## A recipe card for the whole meal

Instead of remembering how to cook each dish and in what order, the recipe card lists every dish, its ingredients and timing; anyone can reproduce the meal.

## Commit the Compose file

A Compose file in the repository lets every new developer start the whole stack with one command.

**Quiz:** What is Docker Compose best suited for?

- [ ] Replacing a database
- [ ] Training machine learning models
- [x] Running multi-container apps for development, testing and simple single-host setups
- [ ] Managing thousands of nodes

*Answer:* Running multi-container apps for development, testing and simple single-host setups. Compose orchestrates containers on one host.