The key difference between CD and DVD is that CD stores up to 700 MB of data primarily used for audio, while a DVD can store 4.7 GB to 17 GB of data and is used for high-quality videos and larger files.
What is CD?
A CD is a digital optical disc developed for storing and playing back audio recordings. It is a round, flat disc made of polycarbonate plastic, typically measuring 12 centimeters (4.7 inches) in diameter. CDs revolutionized the music industry by replacing analog formats such as vinyl records and cassette tapes.
Working of CD
A CD works by using a laser to read the digital data encoded on its surface. The data is stored as a series of tiny pits and lands, representing binary information. When the CD player’s laser shines on the disc’s surface, it reflects differently depending on whether it hits a pit or a land. This reflected light is then converted into electrical signals that can be interpreted as audio or other types of data.
Advantages:
One of the main advantages of CDs over older music formats is their superior sound quality. CDs provide a clear and accurate reproduction of the original recording, free from the hisses, pops, and other audio artifacts often associated with analog formats. Additionally, CDs are more durable and resistant to wear and tear compared to vinyl records or cassette tapes. Their compact size also makes them more portable and easier to store.
What is DVD?
DVD stands for Digital Versatile Disc, though it is also commonly known as Digital Video Disc. It is a digital optical disc storage format used to store high-capacity data, such as high-quality videos and movies, and can also store operating systems. Invented and developed in 1995 by Philips, Sony, Toshiba, and Panasonic, DVDs offer higher storage capacity than CDs (Compact Discs) and can be played in various types of players, including DVD players.
Physical Measurements of a DVD
DVDs come in two sizes:
- 12 cm (120 mm): This is the most common size, typically used for storing software, movies, operating systems, and more.
- 8 cm (80 mm): This smaller size is generally used for portable devices like music players and video cameras.
CD Vs DVD
The major differences between CD and DVD is given below:
| Basis of Differentiation | CD (Compact Disk) | DVD (Digital Versatile Disk) |
|---|---|---|
| Layer of recording | Located on the top of the disk | Located in the middle of the disk |
| Size | 700 MB of data | 4.7 GB to 17 GB of data |
| Layer of Pits | Single pit layer | Double layer of pits |
| Space between Pits | 0.834 micrometres | 0.40 micrometres |
| Space between loops | 1.6 micrometres | 0.74 micrometres |
| Error correction codes | CIRC and EFMP | RS-PC and EFMplus |
| Data transfer rate | 1.4 MB to 1.6 MB per second | 11 MB per second |
| Effect of adhesive labels | Damage to the metal layer after removal | Imbalance in spin after removal |
| Channel bit length | 300 nanometers | 113 nanometers |
| Thickness | 1.2 mm | 0.6 mm |
| Numeric Aperture | 0.45 | 0.6 |