An overview of database normalization

Database normalization is the process of organizing a database in a way that reduces redundancy and dependency within its tables. This is achieved by breaking a large table into smaller ones and linking them through foreign key relationships. Doing so leads to fewer data inconsistencies and improved data integrity. A normalized database results in a modular design that is easy to scale and modify.

Normalization occurs through escalating stages of formal rules called normal forms, ranging from the first normal form (1NF) to the sixth normal form (6NF)—although the first through third are most commonly used and are sufficient for most use cases.

Each normal form builds on the requirements of its predecessor and adds additional criteria that every database table must satisfy. A normal form is considered satisfied when every table in the database meets the criteria laid out for it (and, by extension, its predecessors).

Neglecting normalization...