200-901 Application Deployment and Security Practice Question
A developer is using Docker Compose to define a multi-container application. The application requires a database container and a web server container that must communicate with each other. Which Docker Compose file section defines the individual containers and their configurations?
⚠ Common exam trap
A common mix-up: candidates confuse the services section with networks or volumes, which are supporting configurations rather than container definitions.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
services
In Docker Compose, the services top-level element is where each container is defined with its image, ports, environment, and other settings. Networking, volumes, and configs are separate sections that support those services but do not define the containers themselves. Therefore, services is the correct section for specifying the database and web server containers.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
services
Why this is correct
The services section in a Docker Compose file defines each container as a service, specifying the image, ports, environment variables, volumes, and dependencies. It is the core building block for multi-container applications, allowing containers to be networked together and managed as a single unit. This directly addresses the need to define the database and web server containers.
- ✗
networks
Why it's wrong here
The networks section defines custom networks that services can join, enabling isolation and communication. While important for container connectivity, it does not define the containers themselves or their configurations. The question asks for the section that defines individual containers, which is not the role of networks.
- ✗
configs
Why it's wrong here
The configs section allows you to define configuration data that can be mounted into services, but it does not define the containers. It is used for non-sensitive configuration files. The actual container definitions, including image, command, and environment, are specified under services, not configs.
- ✗
volumes
Why it's wrong here
The volumes section declares named volumes for persistent data storage that can be mounted into services. It does not define containers or their runtime settings. Although volumes are often used with databases, they are supplementary and do not represent the container definitions themselves.
Go deeper
Related to this question
About these practice questions
Courseiva writes every 200-901 question from scratch — 975 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 200-901 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-901 exam.