I want to know more about Terminal Server Restriction.

Please note that the Terminal Server is the same thing as Remote Desktop as called in Windows. The Remote Desktop is used to login to Windows from a remote machine and also on the same machine under a different user account.
With Terminal Server Restriction, you can enable between
Restrict Session
The protected program allows only one Terminal Server session. So you can login to run the application - the first session is console. And, you can login as a second user to run the application.
Block Session
The protected program does not allow any Terminal Server session. So the application can run only under the first user login to the machine.
Below are the steps for testing the two options above.
Restrict Session:
  1. Protect your app using Restrict Session then copy it to a USB drive
  2. Shutdown your system, then restart it.
  3. Log in to a user. e.g. User1
  4. Run the protected app. It can be running.
  5. Switch to log in to a second user. e.g. User2
  6. Run the protected app. It can be running.
  7. Switch to log in to a third user. e.g. User3
  8. Run the protected app. It cannot be running.
  9. Switch back to User1 or User2, then run the protected app, it can be running.
  10. Shutdown your system, then restart it.
  11. Log in to User3.
  12. Run the protected app. It can be running.
  13. Switch to log in to User2
  14. Run the protected app. It can be running.
  15. Switch to log in to User1
  16. Run the protected app. It cannot be running.
Block Session:
  1. Protect your app using Block Session then copy it to a USB drive
  2. Shutdown your system, then restart it.
  3. Log in to a user. e.g. User1
  4. Run the protected app. It can be running.
  5. Switch to log in to a second user. e.g. User2
  6. Run the protected app. It cannot be running.
  7. Switch to log in to a third user. e.g. User3
  8. Run the protected app. It cannot be running.
  9. Switch back to User1 then run the protected app, it can be running.
  10. Shutdown your system, then restart it.
  11. Log in to User3.
  12. Run the protected app. It can be running.
  13. Switch to log in to User2
  14. Run the protected app. It cannot be running.
  15. Switch to log in to User1
  16. Run the protected app. It cannot be running.
If you get the above result, it works fine.