Extracellular vesicles (EVs) are membrane-bound vesicles containing proteins, lipids, and nucleic acids, released by cells through processes like plasma membrane budding or endosomal membrane inward budding. They play a key role in intercellular communication, transferring information between cells. EVs are classified based on their release mechanism and size, with exosomes (30-150 nm) and microvesicles (50-10,000 nm) being the main types. Exosome biogenesis involves the formation of intraluminal vesicles (ILVs) within multivesicular bodies (MVBs), which are then released by fusion with the plasma membrane. This process is regulated by the ESCRT machinery, including proteins like CD9, CD63, and ALIX. Alternative pathways, such as the syndecan-syntenin-ALIX pathway, also contribute to exosome formation. Exosomes are released via MVB fusion with the plasma membrane, and their release is regulated by various Rab GTPases and SNARE proteins. Microvesicles are formed by outward budding of the plasma membrane and are released through different mechanisms, including actin-myosin dynamics and calcium influx. EVs contain a variety of proteins, lipids, and nucleic acids, including mRNA, miRNA, and non-coding RNAs, which are protected from degradation by the limiting membrane. RNA is packaged into EVs through specific mechanisms, such as zipcode sequences and interactions with proteins like AGO2. EVs can be internalized by recipient cells through fusion with the plasma membrane or endocytosis, and their contents can influence cellular functions. The study of EVs is still in its early stages, with challenges in standardizing their classification and isolation methods. Future research aims to better understand EV biogenesis, cargo loading, and their functional roles in health and disease.Extracellular vesicles (EVs) are membrane-bound vesicles containing proteins, lipids, and nucleic acids, released by cells through processes like plasma membrane budding or endosomal membrane inward budding. They play a key role in intercellular communication, transferring information between cells. EVs are classified based on their release mechanism and size, with exosomes (30-150 nm) and microvesicles (50-10,000 nm) being the main types. Exosome biogenesis involves the formation of intraluminal vesicles (ILVs) within multivesicular bodies (MVBs), which are then released by fusion with the plasma membrane. This process is regulated by the ESCRT machinery, including proteins like CD9, CD63, and ALIX. Alternative pathways, such as the syndecan-syntenin-ALIX pathway, also contribute to exosome formation. Exosomes are released via MVB fusion with the plasma membrane, and their release is regulated by various Rab GTPases and SNARE proteins. Microvesicles are formed by outward budding of the plasma membrane and are released through different mechanisms, including actin-myosin dynamics and calcium influx. EVs contain a variety of proteins, lipids, and nucleic acids, including mRNA, miRNA, and non-coding RNAs, which are protected from degradation by the limiting membrane. RNA is packaged into EVs through specific mechanisms, such as zipcode sequences and interactions with proteins like AGO2. EVs can be internalized by recipient cells through fusion with the plasma membrane or endocytosis, and their contents can influence cellular functions. The study of EVs is still in its early stages, with challenges in standardizing their classification and isolation methods. Future research aims to better understand EV biogenesis, cargo loading, and their functional roles in health and disease.