Question

В чем состоит различие между CD- и DVD дисками?В чем их сходство?

Answer 1

Разница в объеме хранимой информации, сходство с способе записи

Answer 2

Разница в объеме хранимой информации, сходство с способе записи..........Сходства-одинаковые размеры (диаметр 120 мм, толщина 1.6 мм), тот же радужный вид. Принцип записи и чтения тоже аналогичный: лазерный луч отражается от металлизированной поверхности ("ямок" и "горок"), причем, отражение от любой поверхности кодирует ноль, а отражение от перехода между ямкой и горкой (при этом луч ослабляется за счет интерференции) - единицу 
На этом сходство заканчивается - дело в том, что в CD используется инфракрасный лазер (длина волны в воздухе 780 нм). В DVD же применяется красный лазер (650/635 нм). Меньшая длина волны позволяет плотнее размещать информацию на DVD-диске. 
Ёмкость DVD сильно превосходит обычный компакт-диск (640 Мб) и составляет 4.38 гигабайта (в смысле 2^30 байт) или 4.7 миллиарда байт, имеется в виду односторонний, однослойный DVD-диск.....

Answer 3

Difference between CD and DVD Discs

CD and DVD discs are both optical storage media used for storing and playing back digital data. While they share some similarities, there are also several key differences between them.

CD (Compact Disc): - CD stands for Compact Disc. - It was introduced in the early 1980s and quickly became popular for storing and playing audio recordings. - CDs have a storage capacity of up to 700 MB. - They use a red laser with a wavelength of 780 nm to read and write data. - CDs are typically used for audio recordings, software distribution, and data storage.

DVD (Digital Versatile Disc): - DVD stands for Digital Versatile Disc. - It was introduced in the late 1990s as an evolution of the CD format, offering higher storage capacity and improved video quality. - DVDs have a storage capacity of up to 4.7 GB for single-layer discs and up to 8.5 GB for dual-layer discs. - They use a red laser with a wavelength of 650 nm to read and write data. - DVDs are commonly used for video recordings, movies, software distribution, and data storage.

Similarities between CD and DVD Discs

While CD and DVD discs have their differences, they also share some similarities:

1. Physical Appearance: Both CD and DVD discs have a similar physical appearance, with a circular shape and a diameter of 120 mm. They have a hole in the center that allows them to be placed on a spindle or disc drive.

2. Optical Storage: Both CD and DVD discs use optical technology to store and retrieve data. They have a reflective layer that reflects the laser beam, and the presence or absence of reflections represents the binary data.

3. Compatibility: Most DVD drives are backward compatible with CDs, meaning they can read and play CDs. This allows users to play audio CDs or access data stored on CD-ROMs using a DVD drive.

4. Data Organization: Both CD and DVD discs use a similar file system called ISO 9660, which allows for the organization and storage of data in a standardized format. This enables easy access and compatibility across different platforms.

5. Writable and Rewritable Formats: Both CD and DVD discs have writable and rewritable formats, allowing users to burn data onto the discs using a compatible optical disc drive. This feature is useful for creating backups, storing data, or creating custom audio or video discs.

In summary, CD and DVD discs differ in terms of storage capacity, laser wavelength, and specific applications. However, they also share similarities in terms of physical appearance, optical storage technology, compatibility, data organization, and writability.