PostgreSQL, commonly known as Postgres, is a free and open-source relational database management system. When you install PostgreSQL for the first time, there is no default password set for the 'postgres' user role. This is done to ensure security and prompt users to set a strong password themselves.

It is crucial to set a strong password for the 'postgres' user to protect the database from unauthorized access. Failure to set a custom password can leave your database vulnerable to cyber attacks and data breaches.

To set a password for the 'postgres' user in PostgreSQL, you can use the command:

ALTER USER postgres PASSWORD 'new_password';

Remember to choose a complex and unique password that includes a combination of letters, numbers, and special characters to enhance security.