A Liter corresponds to the amount of liquid that fits exactly inside a cube with 1 dm of edge. Since the density of water is approximately 1 kilogram per liter, this almost equivalence makes it easy to move from one measurement system to another (in the case of water). In other substances, whether liquid or not, the passage from one unit of measurement to another, is possible only if we know its density. As a matter of curiosity, know that filling a tub to take bath causes that approximately 265 liters of water are consumed, and that a liter of gasoline is enough to contaminate 700 thousand liters of water!
A Cubic Meter equals 1000 liters and corresponds to the volume of a cube with 1 meter edges. Calculating the cubic meters of capacity of a pool is relatively easy, since you simply multiply the length, width and height. But if we want to calculate the cubic meters occupied by the water of a river, then the case changes. In these circumstances, the best we could do is try to get a rough estimate. Did you know that the impressive amount of 2.8 million cubic meters of concrete was used in the construction of the "Three Gorges" hydroelectric dam in China?