There are a lot of ways to track respondents in Surview. By default, the IP addresses of the respondents are being tracked in most collector types.

Anonymous Responses is a collector's setting that gives you options whether not to track or save respondent's identity in survey results.

Email invitation tracking allows you to monitor the actions of your respondents towards the survey sent via email. You can check whether your recipients opened your invitation, clicked through to the survey, responded to your survey, or opted out of your survey in the Overview tab of the collector.

By default, when someone responded to your survey, their IP address is recorded as metadata with your survey results in analyze results tab.