In database terminology, what is a 'relationship'?

A 'relationship' in database terminology refers to the connection between two tables that defines how data in one table is associated with data in another table. This concept is central to relational database management systems, which use tables to store data in a structured format.

When tables are related, they often share a common key, known as a foreign key in the referencing table, that links to a primary key in the referenced table. This relationship allows for data integrity and retrieval, enabling complex queries that can combine and manipulate data from multiple tables.

In a relational database, types of relationships include one-to-one, one-to-many, and many-to-many, each defining a specific way that the tables interact with each other. Understanding these relationships is critical for data modeling, ensuring that the database is organized efficiently and reflects real-world connections between entities.

The other choices discuss different aspects of databases but do not capture the essence of what a relationship between tables is. Descriptions of data types pertain to schema definitions, while methods for storing duplicate data are related to normalization practices, and indexing is related to performance optimization in data retrieval.