Question: In which form the data is stored in CD/DVD?

Answer:

The data stored on a CD (Compact Disc) or DVD (Digital Versatile Disc) is primarily in the form of digital information. CDs and DVDs use optical technology to store data as a series of microscopic pits and lands on the surface of the disc.

The disc is made of a reflective layer, typically aluminum, and a protective layer on top. The reflective layer reflects a laser beam, while the pits and lands modify the reflection pattern. These variations in reflection are read by a laser beam in optical disc drives, allowing the retrieval of the stored data.

The data on a CD or DVD is encoded in a digital format, typically using various encoding schemes such as the Red Book (CD audio), Yellow Book (CD-ROM), or DVD specifications. The data can include various types of content, including audio, video, software, documents, and other files.

CDs have a lower storage capacity compared to DVDs. A standard CD can hold up to 700 MB of data, while a DVD can store significantly more, ranging from 4.7 GB to 9 GB or even more for dual-layer DVDs.

It's important to note that there are different types of CDs and DVDs available, such as CD-R (recordable), CD-RW (rewritable), DVD-R, DVD+R, DVD-RW, DVD+RW, and DVD-RAM, each with its own specifications and capabilities for data storage and recording.