Direct Read After Write (DRAW) is a mode of operation of image discs and CD-ROMs in which data is read immediately after being written. Direct Read After Write is used to compare data, whereby the data recorded on an optical medium
can be directly compared with the source data. Such an optical storage system with "Direct Read After Write" function has two laser beams coming from two independent lasers: one for writing and the second for reading. This makes it possible for the read beam to read the burned-in data immediately after the write beam.