Docker Compose defines and runs multi-container Docker applications. docker-compose.yml file defines services, networks, and volumes. Each image, ports, environment variables, and dependencies. depends_on controls service startup order. Volumes persist data across container restarts. Networks isolate service communication within the application. Environment variables configure services for different environments. Build context specifies Dockerfile location for custom images. Health checks monitor service readiness before dependent services start. Port mapping exposes container ports to host. Scale services for load testing with --scale flag. Override files customize configuration per environment. Secrets manage sensitive data for services. Profiles enable conditional service inclusion. Resource limits prevent containers from consuming all host resources. Init containers run setup tasks before main containers. Logging configuration captures container output. Watch mode rebuilds containers on code changes. Docker Compose is ideal for local development with databases and services. Production orchestration requires Kubernetes or Docker Swarm.