The drawing above shows 100 litres of water as 50 people drinking for a day: each icon represents what one person drinks in a day (2 litres). It is roughly what you drink in a month and a half.
In other units, 100 litres is 0.1 cubic metres or about 26 US gallons. Change the number in the tool or pick another reference for the drawing (glasses, bathtubs, tanker trucks, Olympic pools…) with the "Show" selector.