When they say 20 liters pot (for planting sapling) what it means?

Question

Is it volume? How it is measured?

Answer 1

A five gallon black nursery pot will get it done and you can probably get by with a 3 gallon pot.

Answer 2

That is the size of the pot in units of volume. Theoretically, that pot will hold 20 liters of soil (or water).

Answer 3

That is a little larger than a 5 gallon bucket..it means the volume of soil that the pot will hold..this is not the same as water as suggested here for water has a very different weight and volume than soil...