As far as I can see the VM-100 is a virtual IPS sensor, the VM-100-VSS (Virtual Security System) is a virtual IPS sensor that can only be used with the Intel Security Controller Platform.
What is it you are trying to do?
my teacher asked me compare IPS vm-100 and vm-100 vss. I think those are same, because those base on McAfee network security platform but one for VM EXS and one for VM NSX. But he wants more ...
What is the course you're taking? Is this for the McAfee Network Security Platform Administration course?
Have a look at the the documentation from the McAfee support site, it will explain what the VSS is
Network Security Platform 220.127.116.11-18.104.22.168 VSS Release Notes
Are you taking the Intel Security Certified Product Specialist—NSP exam as part of your course?
Look at page 3 of the above document.
"With this release, Network Security Platform introduces the Virtual Security System model:IPS-VM100-VSS. A Virtual Security System instance is a virtual IPS Sensor. Functionally, a Virtual Security System instance is to some extent similar to IPS-VM100 Virtual Sensors. However, it varies
with respect to deployment method, maintenance, and supported features. When you complete IPS service deployment, Intel® Security Controller orchestrates inline inspection of traffic by the Virtual Security System instances. So, all traffic to and from the protected VMs are inspected for attacks. Even if you migrate a VM to a different ESXi host within the same cluster, the VM is still provided the same IPS service without you having to make any configuration changes."