What databases are created by default when initializing a PostgreSQL cluster?

When initializing a PostgreSQL cluster, the following default databases are created:

• postgres — a system database used for administrative tasks and default connections.
• template1 — a template database from which new databases are created using the CREATE DATABASE command.
• template0 — a reserve template that remains unchanged and is used for creating new databases without user modifications.

Typically, users create their databases based on template1.