I found a definition of return visits like below and it says that it includes "non-cookied visitors."
Shows the number of visits where visit number is greater than 1 and includes non-cookied visitors.
Could anyone explain more about this? I don't understand how they can include "non-cookied visitors".
Here "non-cookied" visitor means visitors who do not accept a tracking cookie. See more details here: v15 Visits Metric Includes Non-cookie Visitors
Adobe tracks those visits with the help of query param collection method (IP Address, User Agent, Gateway IP Address). More details Fallback ID Methods