The paper deals with the interesting optical effect in the nature formed by the refraction and reflection of light by ice crystals in the atmosphere - halos. The first part of the paper describes some type of ice crystals in the atmosphere they have the shape of hexagonal prisms. The second part analysis how and why to originated halo of 22° and halo of 46°. The final part of the paper treats about sundogs and other type of halos. Keywords: Ice crystals in the atmosphere, halos, origin of halo of 22° and halo of 46°, sundogs and other type of halos.