SQL stands for Structured Query Language, and it is a programming language designed for managing and manipulating relational databases.
A primary key is a unique identifier for a record in a database table.
Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.
The GROUP BY clause is used in conjunction with aggregate functions (e.g., SUM, AVG, COUNT) to group the result set based on one or more columns.
UNION combines the result sets of two SELECT statements and removes duplicate rows, while UNION ALL combines the result sets without removing duplicates.