A database (🗺) is a collection of data that is organised structurally according to a specific well-defined set of rules.

Database normalisation is organising data in a database such that errors and anomalies are avoided. To normalise a database, we use the so-called normal forms:

  1. The first normal form requires all the attribute values to be atomic.
  2. The second normal form requires to have no partial dependencies.
  3. The third normal form requires to have no transitive dependencies.

A foreign key is a primary key included within another table. We use foreign keys to relate tables between each other.