Vesicles are small compartments or sacs found in cells that are filled with fluid or other materials. Synonyms for this term include sacs, pouches, bags, bladder, and blisters. Some other related synonyms might include cysts, bubbles, cavities, capsules, and vacuoles. These terms refer to similar structures or spaces within cells, tissues, or organisms that can contain various substances such as nutrients, waste, or secretions. Vesicles are important structures that play key roles in cellular processes such as secretion, communication, and membrane transport, as well as in disease conditions such as cancer and neurodegenerative disorders.