Volume refers to the contents of particular spaces. When you buy a cold drink, you pay for a particular amount of liquid that fills a specific space. This amount of cold drink can also be described as the volume of cold drink. Volumes can be measured with the help of a measuring cylinder, a burette or a pipette.
It depends on the amount of liquid. For lab-scale quantities, I prefer to pour the liquid into a graduated cylinder and compare the level to the graduation marks.Some kind of container makes the measurement easier. If you know the density, you can weigh the liquid and calculate the volume - even if it is an amorphous blob or you don't know the shape.