The chapter introduces the field of Plant Sociology, also known as Vegetation Science, which has evolved from being a minor branch of ecology or a subsidiary of plant geography to a more prominent discipline. The author, Dr. J. Braun-Blanquet, emphasizes the need for a comprehensive overview of the field, including its scope, objectives, and methods. The book aims to provide a unified guide for researchers and students interested in vegetation studies. The introduction highlights the importance of plant societies as social units, formed under specific environmental conditions. The book's structure is divided into several sections, covering the fundamentals of plant coexistence, the composition and analysis of plant societies, the study of plant societies, their development, and their distribution. Key topics include the influence of climate, soil, topography, and human activities on plant communities, as well as the classification and systematization of plant societies. The chapter also discusses the historical development of the field, the significance of pollen analysis in understanding vegetation history, and the methods used to study plant societies, such as the use of diagrams and block schemes. The book concludes with a directory of plant names and societies.The chapter introduces the field of Plant Sociology, also known as Vegetation Science, which has evolved from being a minor branch of ecology or a subsidiary of plant geography to a more prominent discipline. The author, Dr. J. Braun-Blanquet, emphasizes the need for a comprehensive overview of the field, including its scope, objectives, and methods. The book aims to provide a unified guide for researchers and students interested in vegetation studies. The introduction highlights the importance of plant societies as social units, formed under specific environmental conditions. The book's structure is divided into several sections, covering the fundamentals of plant coexistence, the composition and analysis of plant societies, the study of plant societies, their development, and their distribution. Key topics include the influence of climate, soil, topography, and human activities on plant communities, as well as the classification and systematization of plant societies. The chapter also discusses the historical development of the field, the significance of pollen analysis in understanding vegetation history, and the methods used to study plant societies, such as the use of diagrams and block schemes. The book concludes with a directory of plant names and societies.