If cared for properly, a DVD RAM is estimated to be able to last up to 30 years, and through at least 1,000 rewrites. The write speed for a DVD RAM is fairly high, and very accurate thanks to high quality disc defect management. They are frequently used in camcorders and digital cameras to house a high volume of data which can be transferred to another medium before the disc is overwritten.
A DVD RAM uses a type of technology known as phase change on the physical disc to store the data. The disc has a special layer of material made from a mixture of metals which is highly responsive to heat. When the laser makes contact with it, one temperature will cause the alloy to be crystalline, while a higher temperature will turn it amorphous. Thus, it is possible to record binary data onto the disc for playback, and to erase the data and write over it later.