In a database a 'relationship' means two fields in different tables depend on one another.
For example a foreign key in one table will be the primary key in another table, so when one changes the other must change as well.
For example, if you had a table of employee names and the primary key was their employee number that number could also appear in another table as a foreign key.
All these connections between fields in a database forms a 'relational database'.
Challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Relational