What is a relational database query and Explain with an example?

A relational database matches data by using common characteristics found within the data set. The resulting groups of data are organized and are much easier for many people to understand.

For example, a data set containing all the real-estate transactions in a town can be grouped by the year each transaction occurred, the sale price, a buyer's last name and so on. Such a grouping uses the relational model (a technical term for this is schema). Hence, such a database is called a "relational database."

The software used to do this grouping is called a relational database management system (RDBMS). The term "relational database" often refers to this type of software.

Relational databases are currently the predominant choice in storing data like financial records, medical records, personal information and manufacturing and logistical data.