Exosomes, the small extracellular vesicles secreted from cells, have emerged as potent mediators of intercellular communication and are pivotal in therapeutic applications. Currently exosomes are one of the hot areas of research due to their wide application potential in medicine, including disease treatment, diagnosis, and drug delivery. This chapter delves into the architecture and markers of exosomes, shedding light on their complex structure that underpins their diverse functions. It also explores the multifaceted roles that exosomes play in physiological processes, including tissue repair, immune modulation, and cell–cell signaling. Special focus is given to exosomes produced by adipose tissue-derived stem cells (ADSCs). The chapter concludes by emphasizing the promising role of ADSC-derived exosomes in therapy for Alzheimer’s disease, while acknowledging the challenges and future directions in this rapidly evolving field.