Who and how measures the conversion on the site? How is it done in most cases?

Question

Marketing

How sensitive is this? How many people can have access to such information?
(The formulas are clear to me, the process is interesting to me)

Answer 1

With the help of Google Analytics and Yandex Metrika analytics services.
The data is as private as you want it to be.

Answer 2

Yandex.Metrika + Yandex.Webmaster.

How many people can have access to such information?

stupid question, those who need this information to work at the moment should have access: advertising managers - always, auditors / managers - on occasion

Answer 3

Google Analytics and Yandex Metrica + utm tags + goals. How many accesses you issue, so many people will see.

Answer 4

set goals in Yandex metrics and analytics