Which type of database stores data in tables and allows relationships between data through keys?

• A. NoSQL Database
• B. Relational Database
• C. Graph Database
• D. Object-Oriented Database

Answer: (B)

Relational databases organize data into structured tables of rows and columns. The key idea is linking data across these tables using keys. A primary key uniquely identifies a row within a table, and a foreign key in another table points to that primary key, creating a relationship between the two tables. This setup makes it easy to perform joins and maintain data integrity across the dataset, since the relationships are defined and enforced by the database system.

Other database types don’t rely on this fixed table-and-key structure in the same way. NoSQL databases emphasize flexibility and can use document, key-value, or wide-column models instead of predefined tables. Graph databases focus on connections between records using nodes and edges rather than tabular relations. Object-oriented databases store data as objects, mirroring programming language constructs rather than table rows.

So, the one that stores data in tables and enables relationships through keys is the relational database.