Introduction to Databases
What if you needed to pull out only contacts who represent family members? Perhaps another family member might want this information. You would have to flip through the pages of the address book and write down the exact same information onto another piece of paper or perhaps even another address book. This is time consuming. Contact records are duplicated. A change to one phone number means it has to be changed in two or more places: in the address book and anywhere else where you recorded the information.
Over time, your address book will become old and worn. The records in it will be crossed out and changed as people move from one place to another or change their phone numbers. You need a new address book. And then you need to rewrite all of that information again in a brand new book.
It's a lot of work.
What you need is a database.