Patanjali is widely recognized as the compiler of the Yoga Sutras, a collection of ancient texts that form the foundation of the philosophy and practice of yoga. These sutras, or aphorisms, are considered to be one of the most important and influential works in the history of yoga. Patanjali is believed to have lived between 200 BCE and 200 CE, and his exact dates and background are still debated by scholars.

The exact number of sutras written by Patanjali is a matter of some debate, as there are different versions and interpretations of the text. However, the most commonly accepted number is 196 sutras, divided into four chapters or books. These four chapters are known as Samadhi Pada, Sadhana Pada, Vibhuti Pada, and Kaivalya Pada.

The first chapter, Samadhi Pada, contains 51 sutras and focuses on the nature of yoga and the state of samadhi, which is often translated as "enlightenment" or "union with the divine." This chapter outlines the different types of yoga and the obstacles that can hinder one's progress towards samadhi.

The second chapter, Sadhana Pada, contains 55 sutras and discusses the practical aspects of yoga, such as the eight limbs of yoga and the practice of meditation. This chapter also explores the concept of karma and its role in the yogic path.

The third chapter, Vibhuti Pada, contains 56 sutras and delves into the various supernatural powers, or siddhis, that can be attained through the practice of yoga. It also discusses the importance of concentration and the role of the mind in achieving these powers.

The final chapter, Kaivalya Pada, contains 34 sutras and focuses on the ultimate goal of yoga, which is liberation or kaivalya. This chapter discusses the nature of the self and the process of overcoming ignorance and attachment to achieve liberation.

In addition to these 196 sutras, Patanjali is also credited with writing a commentary on the Yoga Sutras called the Mahabhashya, which has been lost. This commentary is believed to have provided further explanation and insight into the sutras and their meaning.

Overall, Patanjali's Yoga Sutras are a concise and profound guide to the philosophy and practice of yoga. They have been studied and revered by yogis and scholars for centuries and continue to be a source of inspiration and guidance for those on the yogic path.