the basics of what a Relational Database is and how it can be used? code example

Example 1: what is relational database

Relational Database =
-Tables are structured related to each other
-Each specific type of domain data is strored
 it's own table

Non-Relational Database =
-There is no relation at all between tables
-Mostly key+value pair : like jSon

Example 2: what is relational database management system

Relational Database Management System
(RDBMS) means that tables in
database are related using
primary/foreign key relationship. Used to store,
modify and retrieve data in the database.

• How are they related?
Primary Key (unique and not NULL)
Foreign Key (duplicate and NULL)

• What type of database system you have expertise with?
RDBMS, such as SQL and Oracle
• Entity Relation Model (ERM):
An entity can be a real-world object, that can
be easily identifiable: student, class, teacher.
• Attributes:
Things that describe the Entity. (student name, age, birthday…)