This category covers issues that relate to the NRPE addon. This addon allows you to execute "local" plugins (like check_disk, check_procs, etc.) on remote hosts. The NRPE daemon runs on the remote host and waits for plugin execution requests from the check_nrpe plugin on the monitoring host.
This category covers issues that relate to the NSCA addon. This addon is designed to accept passive check results from trusted clients in a secure manner and pass them along to the Nagios process by using the external command interface.