Collectors by default store the IP addresses of respondents in survey results, which you may find useful for tracking respondents.
You can prevent IP addresses from being recorded in survey results by making survey results anonymous in your collector settings.
IP addresses can be traced to a computer but not a person. People who share a computer share an IP address. Additionally, some IP addresses are tied to proxy servers, which means multiple computers can share the same IP address.
For example, an organization may have a single phone number that is used to receive incoming phone calls. When a call comes in, it's routed to the appropriate person or extension. The same thing can happen with computer networks. An organization may have a single computer that is used to route Internet connections for all of the computers in that organization's computer network.
If you see multiple responses for your survey with the same IP address, it may be that a single person is responding to your survey multiple times, or it may be that multiple people in an organization are accessing your survey from within that organization's computer network.