The post of Lord Brahmā is meant for very highly elevated, spiritually advanced living beings. When such living beings are unavailable, Lord Viṣṇu, the Supreme Personality of Godhead, expands Himself as Lord Brahmā. This takes place very rarely. Consequently there are two kinds of Brahmās. Sometimes Brahmā is an ordinary living entity, and at other times Brahmā is the Supreme Personality of Godhead. The Brahmā spoken of here is an ordinary living being. Whether Brahmā is the Supreme Personality of Godhead or an ordinary living being, he is known as Vairāja Brahmā and Hiraṇyagarbha Brahmā. Therefore the sun-god is also accepted as Vairāja Brahmā.