146 ◾ Information Systems: What Every Business Student Needs to Know
3. Applications that involve data analysis and decision making may use other database
4. Using databases requires database management soware to store and retrieve data on
behalf of users and applications.
THE DATABASE CONCEPT
A database is an organized collection of data about related items or concepts in the real
At the lowest level, data consists of bytes, because bytes are the basic storage unit of
computers. Data made up of characters, such as names and addresses, ts naturally into
bytes. Other types of data are stored in bytes as well. Most business data consists primarily
of character strings.
ese bytes are grouped into elds or data elements. Each eld in a database contains
one data item that has meaning to the organization. A student’s family name may be a
eld in a university database. Other elds in that database may store the student’s major,
expected year of graduation, hometown, and all the other information universities keep
about their students (Figure 5.1).
Where you t in: The best way to organize data into elds is not always obvious. Should a
person’s name be stored as a unit or as family name and given name* separately? In a shoe
database, should size 8C be stored as one eld or as length (8) and width (C) in separate
elds? This decision should be made by people who know where the data will come from and
how it will be used. When that’s you, understanding database concepts will help you make
A data eld might not consist of characters. A digital photograph in a driver’s license
record is a eld. So is a sound recording of a person’s voice or a scan of the pattern of
It’s best to avoid using “rst name” and “last name,” since name order varies from one culture to another.
8 bits=1 byte
3 bytes=3 letters such as “abc”
3 bytes=number from 0 to 16.7 million
3 bytes=color of one point on a screen
FIGURE 5.1 Bits forming bytes forming a character string, a number and a pixel.