A vacuole is a cell organelle; is it basically a membranous bag filled with fluids. Vacuoles store water and certain materials that are water-soluble. They are present in all plant and fungi cells. They are also found in some species of bacteria and in some animal cells.
In plants and fungi, vacuoles store water and some pigments, and they also provide turgor pressure to support the cells from within. In general, they are larger and more obvious in the plant and fungus cells than in the other organisms discussed here.
In bacteria vacuoles are believed to be a storage organelle. In animals they are used for storage and can be created through the process of pinocytosis. Some types of single-celled animals in the protist group have a special kind of vacuole known as a contractile vacuole, which can gather excess water from inside the cell and expel it into the environment.
A vacuole contains all the cell sap.
There are many types of vacuoles, central water vacuole of plants that is mostly full of water, the contractile vacuoles of Protists, such as paramecia to homeostatically help balance the water continually diffusing in, the food vacuoles of Protists that enter and merge with lysosomes for digestion.