Before we actually start studying the topic of databases we ask ourselves why this topic exists in the computer science curriculum.
Databases are products of computer science used to manipulate data. These systems are important because they are virtually everywhere. We live in an information-rich society. By this we mean that our society relies on the availability of a huge amount of information, everywhere and at any time. We mention just a few instances of databases that we fequently use:
A GSM phone contains a list of names and numbers and perhaps also addresses. It offers a search function and lets you add, delete and modify this information. As the list consists of structured data that can be manipulated through a special interface we call it a database.
Likewise the TV and VCR contain a database, with information about stations and with timer settings.
The vending machine for train tickets at the station has a database with stations and with the price for every ticket (depending on the departure and arrival station).
Shops have a database used by the cashiers' barcode scanners to retrieve the price of every item, and to update the store's inventory.
There are many more databases used in all types of offices, including government, travel agencies, banks and insurance companies.
We are interested in the configuration, optimization and use of databases. We study how to build a database and how to manipulate the data.