What is the meaning of the word Relational in the name of the database type?

Question

Database

I reviewed various lecturers in the hope of finding a detailed explanation of the term "relational" databases. For some reason, everyone says something like "such a name because the table" or "data is stored in tables and therefore the database is called relational". So what does it really refer to? - data to column names, tables to other tables, relationships between tables - one to one, one to many, many to many, etc.?
Whatoooooo????!!!!!
What is the key feature of such databases that led to the inclusion of the word relational in the name?

Answer 1

That's right, a relational database because it is based on the concept of a relationship. And the relationship is the main structural element of such a database, that is, a table.