Size of DVD Rom
DVD ROM sizes and their capacities vary. The most common is the single-sided, single-layer disc with a capacity of 4.7 GB. The single-sided, double-layer has a capacity of 8.5–8.7 GB. The double-sided, single-layer can store 9.4 GB of data. The rare double-sided, double-layer disc has room for 17.08 GB of data.
Overview
DVD ROM stands for Digital Versatile Disc Read Only Memory. Similar to the compact disc in appearance, it is used as media storage disk. What sets it apart from the CD is the capacity. The typical CD can hold 650 MB of data. At most, it can hold 900 MB. As indicated earlier, the most common DVD disc has a capacity of over 4 GB.
DVD ROM Features
There are many kinds of DVDs, and the DVD ROM is just one of them. Because it is read-only, information cannot be written to the disc repeatedly. A perfect example of this is a DVD movie. You cannot edit the contents.
However there are blank DVDs available. These are known as DVD+R or DVD-R. These discs are recordable. The + and – formats are competing with each other. Both types can record videos, audio files images and other files.
How the Disc Works
The disc stores data by way of spiraling pits. Regardless of the DVD ROM size, the data is spaced by only a few nanometers. The trail commences at the center of the disc.
It goes around several times until the outer edge is reached. If the disk has a double layer, the trail goes on to the next material layer. A double-sided disc will have lands and pits on the other side.
Laser Beam
DVD players have a laser beam that runs while the disc is turning. Another component reads the reflection’s intensity as it bounces off the lands and pits. The reflection is transformed into data. These in turn are formed into bytes.
Benefits
The DVD has superseded the videocassette and it is rapidly replacing the CD ROM as well. While the videocassette uses analog technology, the DVD uses digital. A well designed DVD is also free from errors. No matter how often the disc is viewed, the video quality will never change. They also last longer compared to CD ROMs.
The DVD ROM sizes are crucial, but so are the formats. Make sure you get the right type for your needs. Also make sure that the disc can be read by your computer.
