Sitecore EXM creating contact list via importing csv

I have recently came across scenario where I need to create list via importing csv file. I have few queries to understand how it works

1. Does importing csv creates contact for each record in csv?
2. If yes what is the default contact identifier (Name or email)?

Importing contacts for EXM is done by using the List Manager module from Sitecore and there are two ways to import contacts:

• Import contacts to the contacts database.
• Import contacts and add them to a new Contact list.

When you import contacts from a CSV file, the List Manager allows you to manually map the fields, including the unique indentifier, based on which Sitecore will create a new contact or update an existing.

It's recommended to have a strategy when building this unique identifier, like contact's date of birth or zip code in combination with the first name rather than email address - as a person can have multiple email addresses and it might end up having multiple entries in your contacts database.

So to answer your question, Yes - the List Manager will create a new contact if it doesn't find a match based on the Indentifier you provide. The default identifier is the email address.

Official guideline from Sitecore

Import and export contacts from a list https://doc.sitecore.net/sitecore_experience_platform/digital_marketing/the_list_manager/creating_lists/import_and_export_contacts_from_a_list

Important

List Manager uses the contact identifier to identify the contacts in your database and to ensure that unnecessary duplicates are not created when you import new contacts. Therefore, before you import a list of contacts, it is important that you create a strategy for the contact identifier. For example, if you use the contact's date of birth or zip code in combination with the first name, this makes a more suitable contact identifier than an email address alone. Using the email address as the contact identifier can result in a contact appearing multiple times in the database if they have more than one email address.

How to add a contact to a list https://doc.sitecore.net/sitecore_experience_platform/digital_marketing/the_list_manager/creating_lists/add_a_contact_to_a_list

If you do not want to use the email address as the contact identifier, select the Manually map contact identifiers check box and then as the Identifier, select the field in the import file that you want to use as the unique identifier for the contacts.