Raja yoga is also commonly known as Classical yoga and concerned primarily with the mind. Some practitioners also regard Raja yoga as Patanjala yoga. One must be able to tame the mind and body before going into deeper aspects of yoga.
There are a total of eight limbs under Raja Yoga. It comprises Yama, Niyama, Asana, Pranayama, Pratyahara, Dharana, Dhyana and also Samadhi. Yama simply means a set of code of conducts for self-restraint while Niyama refers to religious observances.
Asana is commonly known as integration of mind and body through a series of postural movements while Pranayama comes together with Asanas as Pranayama serves as guide to breathing right that enables a practitioner to integrates the mind and body.
Pratyahara gives an individual inner strength while Dharana requires concentration on a single object. Dhyana is the process of meditation and lastly, Samadhi refers to the super conscious state of an individual.
Bear in mind that Raja Yoga is different from Ashtanga Vinyasa Yoga. Raja yoga requires full concentration of mind using meditation to achieve liberation.