Database: A structured collection of items of data that can be accessed by different application programs.
Table: A group of similar data, in a database, with rows for each instance of an entity and columns for each attribute.
Relational Database: A database where the data items are linked by internal pointers.
Record (database): A row in a table in a database.
Field: A column in a table in a database.
Tuple: One instance of an entity, which is represented by a row in a table.
Entity: Anything that can have data stored about it, for example, a person, place, event, or thing.
Attribute (database): An individual data item stored for an entity, for example, for a person, attributes could include name, address, and date of birth.
Candidate Key: An attribute or the smallest set of attributes in a table, where no tuple has the same value.
Secondary Key: A candidate key that is an alternative to the primary key.
Primary Key: A unique identifier for a table. It is a special case of a candidate key.
Foreign Key: A set of attributes in one table that refer to the primary key in another table.
Relationship: A situation in which one table in a database has a foreign key that refers to the primary key in another table in the database.
Referential Integrity: Property of a database that doesn't contain any values of a foreign key that aren't matched to the corresponding primary key.
Index: A data structure built from 1 or more columns in a database table to speed up searching for data.
Composite Key: A set of attributes that form a primary key to provide a unique identifier for a table.
Entity Relationship Model: Graphical representation of a database and the relationships between entities.
Normalisation: Process of organising data stored into 2 or more tables and relationships between tables, so data redundancy is minimised. First Normal Form: Status of relational database, in which entities don't contain repeated groups of attributes. Second Normal Form: Status of relational database, in which entities in 1NF and any non-key attributes depend upon the primary key. Third Normal Form: Status of relational database in which entities are in 2NF and all non-key attributes are independent.
Database Management System (DBMS): System software for defining, creating, manipulation of database. Data Management: Organisation and maintenance of data in a database to provide the required information.
Data Dictionary: A set of data that contains metadata (data about other data) for a database.
Data Modelling: Analysis and definition of the data structure required in the database to produce a data model.
Logical Schema: A data model for a specific database that is independent of the DBMS used to build that database.
Access Rights: Permissions given to database users to access modify/delete data.
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