Glossary

This glossary contains explanations of some of the terms used in this manual. Cross-references to other entries are given in bold type.
application, database
A database application is a computer program to help users of a specific database. RDMSs provide an application language so that a programmer can create this program.
attribute
A piece of information about an item or entity. For example, hair colour is an attribute of a person, population is an attribute of a town.
column
A database table will usually consist of many rows and columns, just like a table in a book. Each column will store information about an attribute. A table of people may have columns for height, hair colour, eye colour,
database
A structured collection of data.
database application
See application, database.
database management system
A computer program for storing and manipulating data.
DMS
See database management system.
entity
An group of items about which data is stored; for example `stone' or `site'. Entities are usually represented by a table or relation with one or more attributes; an entry in the table, a particular stone, is an instance.
form
A form in a computing context is a structured way of displaying and/or entering data on screen. It is analogous to the more common paper form.
instance
A particular example or entry of an entity; Welwyn Garden City is an instance of the entity `towns'.
normalisation
relation
A special type of table in which (a) every row is unique, (b) the columns are in no fixed order and (c) the rows are in no fixed order. All the tables in a relational database will be relations.
relational database
is a particular way of structuring data which will consist of multiple relations and is manipulated using a relational database management system.
relational database management system
A computer program for storing and manipulating data which has been structured to a form a relational database.
RDMS
See relational database management system.
row
A database table will usually consist of many rows and columns, just like a table in a book. Each row will store information about an entity. A table of people may have a row for each person.
table
A set of data organised in a tabular form with rows and columns similar to a table in a book. A database usually consists of several tables. Tables many be linked via a key field.
tuple
Another name for a row.
variable
A term often loosely used to mean attribute. The term should be avoided as it has other meanings in a computing context.

Mike Gahan 2000-10-18