The amount of space an object takes up is the volume of the object. An ant is tiny. The ant takes up just a little bit of space. It has a small volume. A building takes up a lot of space.
Buildings have large volumes.
The volume of a grain of sand is how much room the piece of sand takes up. The volume of a lake is how much space the lake occupies. Matter that has definite shape and definite volume is a solid . A rock has definite shape and definite volume. It's a solid.