kilo is a prefix used in the metric measurement system used in most countries around the world.
kilo = 1,000 (thousand)
eg A kilometre is 1,000 metres.
eg A kilolitre is 1,000 litres.
eg A kilogram is 1,000 grams.
1 kilometre (km) = 1,000 metres (m)
1 kilolitre (kL) = 1,000 litres (L)
1 kilogram (kg) = 1,000 grams (g)