What is 'Unfiled' in the Contacts tab?
The ‘Unfiled’ group in your contacts list are all the contacts in the ‘Everyone’ list that are not also members of at least one group listed under the ‘My Groups’ section. If the count next to the 'Unfiled' section is 0 then all of the contacts in your Everyone list also exist in at least one of the Groups in your account.
Separating these individuals makes it easy for you to keep your contacts organized. View this article to learn how to manage your groups.