RDBMS: relational database management systems

Relational databases

In the example, we assume that one person lives at only one house number. We do not need to fill in the street name. We can only refer to a unique "id" (identity) given to the street in the table "tblStreets". Each street can only be in one municipality. I can already hear you thinking that several municipalities have a "Village Square," but that is irrelevant in this database. From the moment you select IDstreet=1, for example, the database knows that IDstreet=1 is located in IDcity=1. 

This way you will automatically end up in the correct municipality.  In the user interface, you will first be asked for the postal code, for example. Once you have entered or selected it, choose the municipality. Then you get a list of all the streets in that municipality. When you select the street, you get a list of all your addresses in that street. An additional advantage is that when a street changes its name, the street name automatically gets an update in all addresses.  

Because databases have techniques to link or relate different tables to each other (think IDcity, IDstreet...), in this case we speak of RELATIONAL DATABASES.  Relational databases are used massively in companies, web shops, services, websites, electronic learning environments... massively used. Such databases allow meaningful storage of content presented for users.  

Relational databases are known as RDBMS = relational database management systems.