On the Address info panel you define the customer address: street address, city, country, postal code, phone number, etc.
The phone number to send SMS notifications.
This is another person to contact if the customer or their primary contact is unreachable.
The blind carbon copy. Here you can define a list of emails for one or more recipients, separated by commas, without revealing the information to the customer. For example, to send a copy of every customer's email to your accountant without the customer knowing that, define the accountant's email here.
Here you can leave some notes about the customer's contact details.