Rewritable DVDs, or DVD-RWs, are optical discs that allow users to record, erase, and rewrite data multiple times. They are similar to standard DVDs, but the key difference is their ability to be reused, making them a flexible option for storing files, videos, and other digital content. These discs typically hold about 4.7 GB of data, which is enough for several hours of video or thousands of documents. Rewritable DVDs are compatible with most DVD players and drives, but it's important to check device specifications to ensure compatibility before use.