Exosomes are membrane-bound nanovesicles that contain various biomolecules and are secreted by cells through exocytosis. They play crucial roles in intercellular communication, influencing both physiological and pathological processes. Exosomes can be used as biomarkers, vaccines, and drug carriers due to their ability to transfer biological signals and cargo between cells. However, accurate and efficient identification, isolation, and quantification of exosomes remain challenging. This review discusses the fundamental processes of exosome formation and uptake, their physiological and pathological roles, and their potential applications in translational medicine. Exosomes are involved in immune responses, neural communication, reproduction, development, cell proliferation, and homeostasis. They also contribute to immune disturbances, tumor pathogenesis, neurodegenerative diseases, and pathogenic infections. In translational medicine, exosomes can serve as biomarkers, vaccines, and drug delivery vehicles. For example, exosomes derived from cancer cells can be engineered to induce anti-tumor immunity or stimulate NK cell activity. Additionally, exosomes can be loaded with therapeutic compounds such as proteins, miRNAs, and siRNAs for targeted delivery. The review highlights the versatility of exosomes in diagnostic, prognostic, and therapeutic applications, emphasizing their potential in personalized medicine.Exosomes are membrane-bound nanovesicles that contain various biomolecules and are secreted by cells through exocytosis. They play crucial roles in intercellular communication, influencing both physiological and pathological processes. Exosomes can be used as biomarkers, vaccines, and drug carriers due to their ability to transfer biological signals and cargo between cells. However, accurate and efficient identification, isolation, and quantification of exosomes remain challenging. This review discusses the fundamental processes of exosome formation and uptake, their physiological and pathological roles, and their potential applications in translational medicine. Exosomes are involved in immune responses, neural communication, reproduction, development, cell proliferation, and homeostasis. They also contribute to immune disturbances, tumor pathogenesis, neurodegenerative diseases, and pathogenic infections. In translational medicine, exosomes can serve as biomarkers, vaccines, and drug delivery vehicles. For example, exosomes derived from cancer cells can be engineered to induce anti-tumor immunity or stimulate NK cell activity. Additionally, exosomes can be loaded with therapeutic compounds such as proteins, miRNAs, and siRNAs for targeted delivery. The review highlights the versatility of exosomes in diagnostic, prognostic, and therapeutic applications, emphasizing their potential in personalized medicine.