Endocytosis is a cellular process by which cells internalize molecules, particles, and other substances by engulfing them in a vesicle formed from the cell membrane. This process plays a crucial role in various cellular functions, including nutrient uptake, signal transduction, cell communication, and immune response. Endocytosis involves several different mechanisms, such as clathrin-mediated endocytosis, caveolae-mediated endocytosis, and macropinocytosis, each involving specific proteins and pathways. Dysregulation of endocytosis has been implicated in various diseases, including cancer, neurodegenerative disorders, and infectious diseases. Understanding the mechanisms and regulation of endocytosis is crucial for developing potential therapeutic strategies for treating these diseases.