When a person visits a site, what information does he leave there and what can be learned about the person with the help of it?

Question

Personal Information

Suppose there is a test N on a separate site that is not connected to a social network, and a person passes it without registering on the site in any way. How much information he left just by going to the site (and let's say he confirmed the use of cookies), and what can be learned with the help of it about this person
Z.Y. Particularly interested in the name and social networks

Answer 1

if you fall out vk id - quite a lot
and since at least gender, age

Answer 2

You can learn as much as the person himself allows.
In general, some cookies are already more than enough, since there is such a thing as cross monitoring - this is when one site can load the cookies of others.
The browser itself, in principle, already provides information: on which OS it is running, what modules are installed, your IP -> location and your provider.

Answer 3

This is called “clickjacking” when it comes to social media profiles and other contacts such as phone and mail.