Slaking lime

Lime is slaked with water to form calcium hydroxide or hydrated lime (Ca[OH]₂). Lime is used for a variety of purposes, including mortars and plasters in the building industry, in agriculture to lighten and improve soil in various ways, including reducing acidity and in a number of chemical and industrial processes.

Limestone = calcium carbonate (CaCO₃) – the starting product
Lime = calcium oxide (CaO) – after burning
Quicklime = calcium hydroxide (Ca[OH]₂) – after slaking in water.