Address book and Personal digital assistant

Personal digital assistant and address book are semantically related. In some cases you can use "Personal digital assistant" instead a noun phrase "Address book".

Personal digital assistant noun - A lightweight consumer electronic device that looks like a hand-held computer but instead performs specific tasks; can serve as a diary or a personal database or a telephone or an alarm clock etc..

Address book and personal digital assistant are semantically related. Sometimes you can replace phrase "Address book" with "Personal digital assistant", this phrases are similar.