A CD (Compact Disc) and a DVD (Digital Versatile Disc) are both optical storage media used to store digital data. CDs typically hold up to 700 MB of data, making them suitable for audio files, software, and small data collections. DVDs, on the other hand, can store significantly more data, usually around 4.7 GB for single-layer discs, which allows them to hold full-length movies and larger software applications. Both CDs and DVDs are read by laser technology in devices like CD/DVD players and computers. While CDs are primarily used for music and data storage, DVDs are more commonly used for video content. Despite the rise of digital downloads and streaming, these discs are still used for physical media distribution.