A visitor is an internet user who has come to your website by hasn’t converted to a contact/prospect yet.

A contact is a visitor who has associated his email address and has opted for any of the email communications by sharing unique details like email address/mobile/ external ID.

They are completely anonymous

They are known/signed or identified

Visitors are tracked via cookies

Contacts are identified by their details such as mobile, external ID, email address.

Visitors are generally classified as unique or returning visitors

Contacts are broadly classified into marketing and non-marketing contacts

Visitors do not have a deal associated with it.

A contact may or may not have a deal associated with it, however, they are potential and can be nurtured to become sales-ready.