Here are some common units:

Volume:

* Metric:

* Liter (L): A common unit for everyday fluids.

* Milliliter (mL): A smaller unit, often used for smaller volumes.

* Cubic meter (m³): A larger unit, typically used for industrial quantities.

* Imperial:

* Gallon (gal): A common unit in the United States.

* Quart (qt): A smaller unit, often used for smaller volumes.

* Pint (pt): Even smaller, used for even smaller quantities.

* Fluid ounce (fl oz): A very small unit, often used for measuring liquid ingredients.

Mass:

* Metric:

* Kilogram (kg): The standard unit of mass.

* Gram (g): A smaller unit, often used for smaller quantities.

* Imperial:

* Pound (lb): A common unit for mass in the United States.

Other Units:

* Flow rate: Measures the volume of fluid passing a point per unit time. Units include liters per minute (L/min), gallons per minute (gal/min), cubic meters per second (m³/s).

* Density: Measures the mass per unit volume. Units include kilograms per cubic meter (kg/m³), grams per milliliter (g/mL), pounds per cubic foot (lb/ft³).

It's important to choose the appropriate unit depending on the scale and application. For example, you wouldn't use liters to measure the amount of water in a swimming pool, and you wouldn't use ounces to measure the amount of gasoline in a car's tank.