SIMPLE ADDRESS BOOK
A Simple address book or a name and address book (NAB) is a book or a database used for storing entries called contacts. Each contact entry usually consists of a few standard fields (for example: first name, last name, company name, address, telephone number, e-mail address, fax number, mobile phone number). Most such systems store the details in alphabetical order of people's names, although in paper-based address books entries can easily end up out of order as the owner inserts details of more individuals or as people move. Many address books use small ring binders that allow adding, removing and shuffling of pages to make room.
Software address book
Address books can also appear as software designed for this purpose, such as the "Address Book" application included with Apple Computer's Mac OS X. Simple address books have been incorporated into e-mailsoftware for many years, though more advanced versions have emerged in the 1990s and beyond; and also in mobile phones.
Entries can be imported and exported from the software in order to transfer them between programs or computers. The common file formats for these operations are:
Individual entries are frequently transferred as vCards (*.vcf), which are roughly comparable to physical business cards. And some software applications like Lotus Notes and Open Contacts can handle a vCard file containing multiple vCard records.