Vacuoles are membrane-bound cell organelles. Their function is storage, and they can store food, water, and even cellular wastes. Both plant cells and animal cells have vacuoles, and their function is nearly identical in both cell types. The difference between vacuoles in plant cells and vacuoles in animal cells is size and number. A plant cell will have one large central vacuole, and animal cells will have multiple vacuoles that are much smaller.
The vacuole that is found in a typical plant cell can take up as much as thirty percent of the cell's volume. Cellular conditions are dynamic, and certain conditions can occur in which the vacuole may take up as much as eighty percent of the cell's volume. The main job of the vacuole in a plant cell is storing water and wastes; however, plant cell vacuoles also function to support the cell's shape. Because the vacuole contains liquid, it exerts an outward pressure on the cell that helps to prevent the cell from collapsing inward due to the surrounding outside pressure.
The vacuole is not the only difference between a plant cell and an animal cell. Plant cells also have a cell wall in addition to the cell membrane. Animal cells only have the cell membrane.