Polysaccharides have attracted much attention owing to their immense biological and pharmacological usage such as in medical, chemical, nanotechnology, pharmaceutical, material science and food industry. Polysaccharides being one of the essential macromolecules, can be obtained from various sources viz., plants, microorganisms, algae and animals. The diverse applications of polysaccharides in various pharmaceutical or biopharmaceutical fields is mainly due to their physicochemical characteristics that makes them prone to physical and chemical modifications to enhance their properties. By examining the multifaceted aspects of polysaccharides, the present chapter endeavours to give insight into their significance in diverse fields, covering the classification and most recent updated applications. Additionally, the chemistry and structure of various polysaccharides in nature have been addressed. Finally, future trends of the polysaccharides for usage in various fields, including tissue engineering is summarized.