a database is a collection of related data that is organised for convenient acess and some examples include phone contacts, iTunes, search engines or the yellow pages. the yellow pages is a database because it is a collection of data and it's organised into different catagories so it's easy to locate the right information you are looking for.
some advantages to the electronic databases are that it's easier because you don't have to manually flip thrugh the book to find the information, it includes a map so you can get directions, it's faster, it includes all of Australia not just one state and it takes up less room because it's online.
some dangers or disadvantages to the electronic version are that it is easy to stalk or find personal information like an address.