---
title: "About Builds"
---

# About Builds

Builds are instances of `packer build` being run within Atlas. Every
build belongs to a build configuration.

__Build configurations__ represent a set of Packer configuration versions and
builds run. It is used as a namespace within Atlas, Packer commands and URLs. Packer
configuration sent to Atlas are stored and versioned under
these build configurations.

These __versions__ of Packer configuration can contain:

- The Packer template, a JSON file which define one or
more builds by configuring the various components of Packer
- Any provisioning scripts or packages used by the template
- Applications that use the build as part of the [pipeline](/help/applications/build-pipeline) and merged into the version
prior to Atlas running Packer on it

When Atlas receives a new version of Packer configuration and associated
scripts from GitHub or `packer push`, it automatically starts a new
Packer build. That Packer build runs in an isolated machine environment with the contents
of that version available to it.

You can be alerted of build events with [Build Notifications](/help/packer/builds/notifications).