You need a license on every computer where CLScan is executed.

Case 1:
You have a single computer that needs to use one or more locally or network installed scanners.
You need a single license because CLScan is executed just on one computer.

Case 2:
You have an application that will use CLScan. That application is distributed to different computers.
Every computer needs its own license. If there are many computers, it is more economical to buy 1 CLScan redistributable.
Every computer needs to have its own copy of a redistributable license.

There’s no limit to how many computers can use a single redistributable license.

Case 3:
You have a server app and a scanner installed on the server or server is able to use some network scanner.
You need a single license because CLScan is executed just on one computer.

Case 4:
You have a server app. You have a client app that uses a scanner installed locally.
Every client computer needs its own license. If there are many computers, it is more economical to buy 1 CLScan redistributable.

Case 5:
You have a server app in a remote-desktop-environment. Your clients use your server app but they want to use their local scanners from the server app. You need 1 single CLScan license for the server. You also need TSScan product - www.terminalworks.com/remote-desktop-scanning