Both CDs and DVDs are great for file storage. Both CDs and DVDs have pits or dark spots on the medium encoding the data. Generally speaking, a DVD can store more data than a CD, which is one of the reasons why CD contains the polycarbonate substratum on only one side while it is on both sides in DVDs. In our word today, CDs and DVDs have become a popular technology and these two terms have also become synonymous with the concept of a compact disk. A laser beam is focused in the CD or DVD to read the content (data) that is stored in the bits form of the disk and to write the content.
Definition of CD: The CD (Compact Disc) is a storage device that’s wont to store data. It uses a singular method of encoding during which a 14-bit code indicates a byte and this encoding technique also helps in error detection. These are literally made to exchange floppy disks that were wont to store files and programs from the computer. Usually, a standard CD can store about 700MB of data; that means people can store CD-quality audio that can last for about 80 minutes or video lasting about 60 minutes. Standard CDs are widely used to store music, files, drivers, programs, etc.; initially, CDs provided more storage capacity than the hard drive of the machine, but hard drives outweigh CD by a mile with the technology of today.
Definition of DVD: The DVD (Digital Flexible Disk) is an optical medium for physical data storage, too. It offered an alternative to the videotape used in VCR (Video Cassette Recorder) and CD-ROM used in PC as the DVD would accumulate seven times as much data as the CD. A standard DVD can hold 4.7 GB of data; So DVD is widely accustomed store large files like video and films. A DVD is made from the identical material because the CD but the method and therefore the layers are different; it’s used from both of the edges like two CDs are sticking together. The upper rate of DVD allowed for better video quality, and also the increased space for storing (including the dual-layer technology) allowed a full-length movie to suit on one disc, with room left over for special features.
There are a few differences between CD and DVD, which are given below:
CD (Compact Disc) –
- A standard CD can store about 700MB of data.
- CDs are created with the intent of keeping both audio and program data.
- CDs read mechanism is 780 nm wavelength (infrared and red edge) semiconductor laser, 1200 Kib/s (1×)
- The recording or metal layer at the top of the disk is found in CD.
- A CD includes 1.6 micrometers of space between the spiral tracks and 0.834 micrometers between the pits on the disk.
- In CD, CIRC and EFMP are used as the error correction codes.
- Removing a CD’s adhesive label will cause the CD to suffer serious harm.
- The channel bit length in CD is 300 nanometer.
- Types of CDs are: CD-R, CD-RW, CD-Text, CD + Graphics, CD + Extended Graphics, Super Audio CD, CD-MIDI, CD-ROM, Video CD, Super Video CD, Photo CD, CD-I, Enhanced CD, VinylDisc and Bootable CD.
DVD (Digital Versatile Disk) –
- A standard DVD can hold 4.7 GB of data.
- DVDs are made for the purpose of holding video files, movies, a considerable number of programs, etc.
- DVDs read mechanism is 650 nm laser, 10.5 Mbit/s (1×)
- In DVD, in the middle of the disk is the recording or metal layer.
- The spiral loops in DVD are 0.74 micrometers apart, and the pit gap is 0.4 micrometers apart.
- In DVD, RS-PC and EFMplus are used as the error correction codes.
- When the DVD’s adhesive label is removed it causes the spin imbalance.
- But in DVD the channel bit length is 113 nanometer which is less than the channel bit length of the CD.
- Types of DVDs are: DVD-RW, DVD+RW, DVD-RAM, and Blu-Ray.
Both CDs and DVDs are great for storing media files. They’re the optical recording medium where CD was devised as an audio storage format while DVD is employed because of the universal storage format. CDs and DVDs are made using polycarbonate plastic, which is approximately four one-hundredths (4/100) of an in. or 1.22 mm thick. The capacity is the biggest difference between CD and DVD. The latter technology DVD can hold data about 7 times quite CD and its format efficiency is additionally 32% greater than a CD.
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