What is volume? It is a word that can have several meanings, such as a number in a series of books; but in terms of measurement we are looking at how much space an object or liquid occupies. For example, if I have an empty bottle and want to fill it up, how much liquid can fit in there?
Volume is measured using litres and millilitres, but for larger objects it can be measured in cubic metres. An alternative to millilitres is cubic centimetres, in that they are the same size, just different names, both measuring small volumes. Let us see how this looks below:
If we take a small cube, which has each side measuring 1 centimetre in length, we have a volume of 1 cubic centimetre.
If we have something similar but bigger, so that each side is 10 centimetres in length, we see, from the image below, that it has a volume of 1000 cubic centimetres, which we also call 1 litre:
But not everything is a nice perfect cube shape, therefore volumes are not always easy to measure for solid objects, but usually we only want to know the volume of something liquid. We can use litres and cubic centimetres, or even cubic metres, as well as millilitres, for measuring solid objects, or space that something might fit into, e.g. the space of your car boot, as well as for liquids such as drinks, water, and for gas.
For easy reference:
1 cubic centimetre = 1 millilitre
1000 millilitres = 1 litre = 1 cubic decimetre
1000 litres = 1 cubic metre
Here are some examples:
Item  Volume  
Bottle of water bought from a supermarket  Small: 500 ml medium: 1 litre large: 2 litres 

Luggage space in car boot 
Small car: 200 litres Medium car: 380 litres Large car: 500 litres Estate car: 540 litres People carrier: with all seats upright, 330 litres with only 2 rows of seats, 800 litres with 1 row of seats, luggage piled up to the roof, 2.6 cubic metres (2600 litres) 

Fridge internal capacity 
Small: 100 litres Medium: 150 litres Large: 350 litres 

Wine 
Small glass: 150 millilitres Larger glass: 250 ml Bottle: 75 cl (750 ml) 

Glasses 
Small glass: 220 ml Pint glass: 568 ml 

Tea 
Tea mug: 250 ml Tea pot: 1.1 L = 1100 ml 

Milk carton  Carton of milk, e.g. soya milk: 1 litre  
Kettle  Max usable capacity: 1.7 litre  
Bath  225 litres  
Swimming pool  If we take large sized pool, length 50 metres, width 25 m, shallow end depth of 2 m, deep end depth of 3 m, then the volume is 3125 cubic metres, which equates to 3 125 000 litres of water.
A smaller pool, such as pictured, with length 18 m, width 6 m, depths 1 m to 2 m, has a volume of 162 m^{3} which is 162 000 litres. 