Lightweight concretes are sort of special concretes with lower density than normal concrete. Reducing density can be achieved in many ways, by creating voids in concrete, by using aggregates with a lot of voids or by creating interspace between aggregate grains. These processes will sacrifice certain properties like compression strength to improve other properties like insulation. The basic classification of lightweight concrete is into lightweight aggregate concrete, cellular concrete and single-grain aggregate concrete. Pozzolan, pumice and EPS grains are used to make lightweight aggregate concrete. Each type of agrregate provides specific advantages and disadvantages for final mixture. Cellular concretes are recognized by voids which can be made several ways. They can cover wide range of density and wide range of application. Properties of lightweight concretes depend on type of lightweight concrete, but in general they have lower value of density, lower load capacity and better insulation properties than normal concretes. Application area of lightweight concretes is extremely wide, from creating load-bearing elements with good insulation properties to groundworks and filling materials. Various researches and new receptures seek to improve properties of lightweight concrete and patent new types that will be universal.