How do we identify known and unknown visitors?

Known visitors are usually identified by the information they have provided, including sign-up forms that might contain their email, name, or other data. The system recognizes these visitors when they interact with your website/campaigns, if their information already exists in the database.

Unknown visitors, on the other hand, may have not provided any identifiable information to MA. So they will be considered anonymous until specific data is found. They are usually tracked with cookie information and session IDs even if they are a returning visitor until further information is tagged to that visitor via a sign up, forms, or contacts import through integration.