It means You can let friends and family browse the Internet on your computer and still keep your account information private by using Guest mode.
When friends and family members browse as guests on your computer, none of their browsing history or cookies are saved. They also can’t see or change your Chrome information or settings.
Both Guest mode and Incognito mode are temporary browsing modes, but there are some basic differences between them.
Important: Neither Incognito mode nor Guest mode makes you invisible on the web. Websites you visit, your employer, or your service provider can still see your browsing activity.