Contacts(The UI label in Messenger for the results list of a contacts search); contact(A person, inside or outside your organization, for whom you have created an entry where you can save several types of information, such as street and e-mail addresses, telephone and fax numbers, and Web page URLs)
Active Directory contact(An Active Directory object that contains information about an individual such as name, address, and job title. It can include a foreign e-mail address)