Raja yoga is a term with different meanings depending on context; in the 1900s, Swami Vivekanada equated it with the sutras of Patanjali. Raja means best, chief, or king; when used in yoga it means the highest state of yoga practice or striving for samadhi (bliss). This is the feeling that you achieve in savasana after a well afforded practice; after you’ve pushed yourself and worked hard. Hatha yoga is described as the way to achieve raja yoga when combined with the sutras of patanjali.
Raja is a term that has undergone changes over time until it was most recently equated with the yoga sutras by Swami Vivekanada, but it has always referred to a style of yoga that attempts to make unison with the Brahman, or universal divinity. Eight different steps have been mentioned numerous times and have also evolved over time as the usage of the word has evolved since it was used in the Bhagavad Gita. It has always been considered a type of yoga.
Raja yoga is similar to a path of meditation towards the divine, assimilating the philosophy of samadhi and complete awareness into everyday life. Historically, there are three goals of Raja yoga: an altered state of higher consciousness, an uncovering of the soul, and the yogic traditions of isolation, meditation, and retrospection. It is a term used to largely define the goal of the practices of hatha yoga.