Incognito doesn't do much beyond not account for your history.

It's good if you and your mom use the same computer and you don't want her browser to auto complete with your porn searches. Not for much else.

It's usually a number of different data points about your browser like the user agent string that identifies what browser you use and what OS, screen resolution, language settings, timezone, whether or not you use and adblocker etc... and of course IP addresses