Update help

src/azure-cli/azure/cli/command_modules/vm/_params.py

@@ -497,7 +497,7 @@ def load_arguments(self, _):
                    help="The eviction policy for virtual machines in a low priority scale set.", is_preview=True)
         c.argument('application_security_groups', resource_type=ResourceType.MGMT_COMPUTE, min_api='2018-06-01', nargs='+', options_list=['--asgs'], help='Space-separated list of existing application security groups to associate with the VM.', arg_group='Network', validator=validate_asg_names_or_ids)
         c.argument('computer_name_prefix', help='Computer name prefix for all of the virtual machines in the scale set. Computer name prefixes must be 1 to 15 characters long')
-        c.argument('orchestrator', help='Choose how virtual machines are managed by the scale set. In Virtual Machine mode, you manually create and add a virtual machine of any configuration to the scale set. In ScaleSet VM mode, you define a virtual machine model and Azure will generate identical instances based on that model.',
+        c.argument('orchestrator', help='Choose how virtual machines are managed by the scale set. In VM mode, you manually create and add a virtual machine of any configuration to the scale set. In ScaleSet mode, you define a virtual machine model and Azure will generate identical instances based on that model.',
                    arg_type=get_enum_type(['VM', 'ScaleSet']))
 
     with self.argument_context('vmss create', arg_group='Network Balancer') as c: