Manifests are files that contain code to define a set of resource and their attributes. A resource is any configurable part of a system. Examples of resources include packages, services, files, users and groups, SELinux configuration, SSH key authentication, cron jobs, and more. A manifest defines each required resource using a set of key-value pairs for their attributes. For example:

package { 'httpd':
  ensure => installed,
}

This declaration checks if the httpd package is installed. If not, the manifest executes yum and installs it.

Manifests are located in the manifest directory of a module.

Puppet modules also use a test directory for test manifests. These manifests are used to test certain classes contained in your official manifests.

Modules can contain static files that Puppet can copy to certain locations on your system. These locations, and other attributes such as permissions, are defined through file resource declarations in manifests.

Static files are located in the files directory of a module.

Sometimes configuration files require custom content. In this situation, users would create a template instead of a static file. Like static files, templates are defined in manifests and copied to locations on a system. The difference is that templates allow Ruby expressions to define customized content and variable input. For example, if you wanted to configure httpd with a customizable port then the template for the configuration file would include:

Listen <%= @httpd_port %>

The httpd_port variable in this case is defined in the manifest that references this template.

Templates are located in the templates directory of a module.

Plugins allow for aspects that extend beyond the core functionality of Puppet. For example, you can use plugins to define custom facts, custom resources, or new functions. For example, a database administrator might need a resource type for PostgreSQL databases. This could help the database administrator populate PostgreSQL with a set of new databases after installing PostgreSQL. As a result, the database administrator need only create a Puppet manifest that ensures PostgreSQL installs and the databases are created afterwards.

Plugins are located in the lib directory of a module. This includes a set of subdirectories depending on the plugin type. For example: