PostgreSQL is a database management system based on Unix platform. It allows you to add, access, and process stored data. The SQL part of PostgreSQL stands for "Structured Query Language" - the most common standardized language used to access databases.
Unlike with other databases, a PostgreSQL database cannot be created without a user. You must stick to the following sequence:
Note: The first user in the list of users is the owner of a database, however the database can be used by others who obtain permissions from the owner.