True or False: If site.pp contains at least one node definition, it must have one for every node.

The statement is false. In Puppet, the site.pp manifest does not require that every node in your infrastructure be explicitly defined within the file. While it is common to define specific nodes, you can also utilize the default node or include classification mechanisms to handle nodes that do not have explicit definitions. This flexibility allows for a more manageable and scalable configuration, where nodes can inherit properties or behaviors from a default definition or through external classification tools.

If you only define some nodes, those nodes will have their specified configurations applied, and any nodes not directly defined can still receive configurations through the default node or through hierarchies set up in other manifests or with tools like Puppet Enterprise's classification dashboard. This approach helps to reduce complexity and avoid redundancy in your Puppet configurations.