Which command is primarily used to execute Puppet manifests?

The command primarily used to execute Puppet manifests is "puppet apply." This command is designed to apply the resources defined in a Puppet manifest file directly on the local system where the command is executed. When you use "puppet apply," it takes the specified manifest, evaluates it, and then makes the necessary changes to ensure that the system's state matches the configuration defined in that manifest.

This functionality is particularly useful for testing and applying configuration changes without involving a Puppet master server. It enables administrators to manage nodes individually, perfect for environments where a full Puppet infrastructure may not be deployed.

In contrast, the other options do not serve the primary function of executing manifests. "Puppet start" and "puppet run" do not exist as standard Puppet commands, while "puppet execute" is also not a recognized command in Puppet's set of utilities. Thus, "puppet apply" stands out as the correct choice for executing Puppet manifests.