---
title: Concepts
description: The few ideas everything else on ops is built from.
order: 2
---

- [Projects and environments](projects-and-environments.md): what a project holds, and the
  production, staging, development and preview environments inside it.
- [Resources](resources.md): services, databases, domains, secrets, buckets and jobs, and
  who may change them.
- [Deployments and previews](deployments-and-previews.md): what happens between a push and
  a running service, rollback, promote, and an environment per pull request.
- [The project file](project-file.md): `.ops/project.ts`, the repository's description of
  what it deploys.