---
title: Overview
description: Explainer on the ways to set, use and manage environment variables in Compose
keywords: compose, orchestration, environment, env file
---
{% include compose-eol.md %}

Environment variables can help you define various configuration values. They also keep your app flexible and organized. 

This section covers:
- The various ways you can [set environment variables in Compose](set-environment-variables.md).
- [How environment variable precedence works](envvars-precedence.md).
- The correct syntax for an [environment file](env-file.md).
- Changing pre-defined [environment variables](envvars.md).