Currently, DVD is divided into two main categories: single layer DVD - has a capacity of 4.7 GB and double DVD layer - has a capacity of 4.7 GB x 2 = 9.4 GB. If the DVD player does not have a double layer symbol, it will not be able to read this format.
Distinguish different types of DVDs in the market Picture 1DVD ± R (DVD recordable) : DVD discs can only be recorded once. DVD-R: The format first appeared and originally intended to save the image. DVD + R: same as -R but allows viewing without a complete disc.
DVD ± RW (DVD Read Write) : DVD is capable of erasing and writing multiple times. Usually a DVD ± RW disc is capable of recording, erasing no less than 1,000 times. The capacity of this type of disc is 4.7GB. DVD + RW discs are often used for storage, while DVD-RW is often used until recording. Currently most of the discs on the market are DVD ± RW, not just DVD + RW or DVD-RW.
Although DVD is still the most popular disk technology today, it will soon be replaced by two new discs, HD DVD and Blue-ray.