Limit how many times a survey can be taken from one device (e.g. laptop, desktop, mobile phone). By default, a device can only log one response.
This can be useful if a survey is going to be taken on a public or shared device. The IP address will still be logged, so the results can help you see if results have skewed.
A cookie is placed on the respondent's computer. This will not allow them to take the survey more than once from a single device. If a user uses two devices, they can still take the survey twice. This only applies to web link and embedded surveys.