During a `packer build`, the process list shows `packer-` prefixed applications. One of those applications is the Packer binary, and the rest are plugins. Packer launches one plugin process for each component in the build.
The Packer binary has a set of built-in plugins that it can find and run automatically. You can also define a list of external plugins in your template for Packer to run and communicate with throughout the build. These external plugins extend Packer functionality without modifying the core source code.
- **Built-in Plugins:** Use [builders](/docs/builders) to create machines and images, [data sources](/docs/datasources) to fetch data, [provisioners](/docs/provisioners) to install and configure machine images, and [post-processors](/docs/post-processors) to perform additional tasks after provisioning
- **External Plugins:** Review the documentation for [available external plugins](/plugins) not included with the Packer binary
- **Installing Plugins:** [Installation Guides](/docs/plugins/install-plugins) to add external plugins to your Packer template and install the binaries
- **Developing Plugins:** Get started [creating custom external plugins](/docs/plugins/creation)