The Rizom Host ID is a string of text which uniquely identifies your, or any other user’s computer to Rizom-Lab. It looks like something like this:
U...1...STANDALONE...W...2017...0...2...master...ETHERNET=3497F668BD75,ETHERNET=005056C03001,ETHERNET=005056C02008,HOSTNAME=Aaron...8241

When you’re not using RizomUV, the string does nothing. It’s not spyware. What it does,is to provide a basis for Rizom-Lab to generate a license file to use on your computer. The string of text is unique for each computer. Therefore, each RizomUV license will be associated to at least one Rizom Host ID (you can have two per computer,  max), and the subsequently generated license file using the Rizom Host ID is what allows a computer with a current license to run the software.