In the recent decade, extracellular vesicles (EVs) have been released from nearly all the kingdoms, modulating intercellular communication and maintaining the human body's homeostasis by regulating different cellular processes. Among EVs, exosomes are the emerging field in biopharmaceuticals. They have lipid bilayer ranging from 30 to 150 nm in size and encompass DNA, RNA, protein lipids, etc. Their sources are widespread, easy to acquire, and cost-effective in manufacturing. This review focuses on the detailed classification of exosomes existing in nature, knowledge and application of omics, therapeutic, diagnostic and theranostic application of exosomes. It covers diseases such as cancer, infectious diseases (viral, bacterial, fungal infections), neurodegenerative diseases, metabolic diseases, lifestyle diseases (diabetes, cardiovascular, gastric disorder (IBD)), autoimmune disorders and their biodistribution. This article unfolds the recent progress in the exosomes arena and covers all the regulatory considerations (FDA, EMA, and other nations) involved with it. Moreover, a detailed discussion about clinical trials and its manifestation with exosomes and challenges associated with their isolation procedures, reproducibility, and safety concerns.