This field, which appears under the ‘Common settings’ tab of a Service definition, is used to specify the command that should be run in order to check the status of the service. The command used varies according to the service to check. The description usually matches (or partially matches) the service name.
By default this check is defined and active, and uses a command to run for a service. You may also remark that depending on the command you select under the ‘Check command” field, the “Command view” will automatically be adjusted to display the corresponding command parameter used by the command.