As explained previously, data is recorded on CDs through the use of little spots of different reflectivity. This means that the smaller the size of the spots used, the more data can be incorporated onto a single disc. It is for such reasons that blue-laser data storage is drawing a lot of attention these days. The red lasers used until now create spots of about 1 micron (1,000 nanometers) in diameter, whereas blue lasers can create spots half this size, about 500 nanometers in diameter. This means that, calculated simply, four times as much data can be stored on a disc of the same size as a CD or DVD.