Which command will display all installed modules from the Puppet Forge?

The command that displays all installed modules from the Puppet Forge is "puppet module list." This command provides a comprehensive overview of the modules that have been installed on the Puppet system, including their names, versions, and the paths where they are located. By issuing this command, users can easily verify the modules they have at their disposal for managing and configuring their infrastructure.

In contrast, the other options do not fulfill this specific requirement. For instance, "puppet module show" is typically used for retrieving detailed information about a specific module but does not list all installed modules. The command "puppet list modules" does not exist within the Puppet command set and is therefore invalid. Similarly, "puppet modules installed" is not a recognized command and would result in an error. Therefore, "puppet module list" stands out as the correct option for displaying all installed modules from the Puppet Forge.