Why use additional ips on VPS server ?

Hello everyone,
I have a VPS server from contabo with additional IP to my server. I have created two nameservers using those IPs ns1 and ns2. besides using this additional IP for the second nameserver what are the other uses for them? Do I benefit from those extra IPs? Are there any other benefits? How can use the second IP for other things on my server. I am sorry for asking this silly question, I am new to this server thing. I have set up my server from tutorials and learned many things from the community. I am running cwppro on my VPS.

Please help.
Thanks and Regards.