File with a .CDB extension contains a database of contacts of cell phones with the Symbian operating system. A record within the database may contain a name, address or a telephone number.

CBD file is usually named – contacts.CBD and it can be converted into a more universal format – vCard. CDB files are created during transfer of data from a cell phone, for instance a Nokia, to a PC. They are used to sync contacts are to create their backup copies.