Vesicle trafficking is the process by which small membrane-bound sacs, called vesicles, transport proteins and other molecules within cells. These vesicles bud off from one membrane, carry their cargo, and then fuse with another membrane, allowing the contents to be delivered to specific locations, such as the Golgi apparatus or the cell membrane. This process is essential for various cellular functions, including secretion, nutrient uptake, and the recycling of cellular components. Proteins and lipids are often packaged into vesicles, which are guided by specific signals and proteins to ensure they reach their correct destination within the cell.