• Relational Database: A relational database is a collection of information that organizes data in predefined relationships where data is stored in one or more tables (or "relations") of columns and rows, making it easy to see and understand how different data structures relate to each other. 
    • Examples: MySQL, Oracle Database, MariaDB, PostgreSQL, Microsoft SQL Server etc.

  • Key terms: 
    • Table – Basic data structure 
    • Column – One kind of data in a table 
    • Row – Instance of a table 
    • Field – Value found at the intersection of a row and a column 
    • Primary key – Unique identifier for each row 
    • Foreign key – Column that refers to the primary key of another table 

  • Everyday life and Database: 
    • ATM machine
    • Making calls on the phone 
    • Booking reservation tickets 
    • Controlling traffic signals