How to define an auto increment primary key in PostgreSQL

To define a primary key that auto increments in PostgreSQL you create the table row using the SERIAL type with the PRIMARY KEY constraint, like this:

CREATE TABLE cars (
  id    SERIAL PRIMARY KEY,
  brand VARCHAR(30) NOT NULL,
  model VARCHAR(30) NOT NULL,
  year  CHAR(4) NOT NULL
);

In MySQL / MariaDB this is equivalent to

CREATE TABLE cars (
  id    INT(11) NOT NULL AUTO_INCREMENT,
  brand VARCHAR(30) NOT NULL,
  model VARCHAR(30) NOT NULL,
  year CHAR(30) NOT NULL,
  PRIMARY KEY (`id`)
);