The main difference between DVD+/-R and DVD+/-RW is that the R is a write-once format. Data can be burned on the DVD only once. On the other hand, an RW disc can be erased and rewritten hundreds of times.
|This comparison chart has not been created yet. Create it or review the information below.|
Write once formats use a single write laser to change a dye layer affecting the opacity of the dye. The laser darkens spots on the recording layer (dye layer) to record information. Rewritable media use a phase change recording layer where the write laser changes the polarization of the recording layer (usually a metallic material) by crystallizing it. In order to erase this layer so new data can be added, an erase laser (usually the recording laser refocused to be wider then that needed to record data) is used. This erasing function heats the layer causing it to become amorphous again as it was in the blank state.