Vesicles are small, membrane-bound sacs found within cells. They play a crucial role in transporting materials, such as proteins and lipids, to different parts of the cell or to the cell membrane for secretion. Vesicles can form from the budding off of larger organelles, like the endoplasmic reticulum or Golgi apparatus, and are essential for various cellular processes. There are different types of vesicles, including transport vesicles, which move substances between organelles, and secretory vesicles, which release materials outside the cell. Additionally, lysosomes are specialized vesicles that contain enzymes for breaking down waste and cellular debris, contributing to the cell's overall maintenance and health.