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What Is a Database? A database is any collection of information with an internal structure that is organized so that its contents can easily be accessed, managed, and updated. Databases contain aggregations of data records or files, such as sales transactions, inventories, customer profiles, and books in a library. What is important for the searcher to know is how the database is structured and which fields in the database can be searched. Database searches are performed by searching specific fields. The records you retrieve depends on the fields you choose to search. Records The largest unit of a database is referred to as a record. A database record is a condensed description of content and representation of the actual "thing." In the database of its inventory, Bruno's has a record for everything on its shelves, even for bags of sour cream and onion Tostitos. Cool ranch Fritos have a different record. Your address book has records for the people you want to contact. Fields Fields are units of a record that contain unique information. The record for sour cream and onion Tostitos in Bruno's lists the size of the bag, the flavor of the chips, the manufacturer, the distributor, the price, the number of bags on the shelf, the number of bags in the store, with a bar code attached to the record. These are the record fields. Fields provide the database user with a set of meaningful information which can be searched. For each of the people in your address book, you may record their name, street, city, zip code, phone number, cell phone number, fax number, e-mail address, birthday, and so on. These are the fields of your address book "database." Although there are many different types of databases organized for a variety of purposes, in this tutorial we will focus on three specific types of databases:
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