Which method for storing writable data on a DVD is used for DVD-RW and DVD+RW discs?

The correct method for storing writable data on DVD-RW and DVD+RW discs is the crystalline-changing method. This approach relies on a special type of dye that changes its crystalline structure when exposed to a specific laser light during the writing process. When the laser heats the dye, it transitions between amorphous (non-crystalline) and crystalline states. This transformation effectively marks the data onto the disc.

The significance of this method is that it allows for the rewritable feature of DVD-RW and DVD+RW discs. Because the crystalline structure can be altered multiple times by applying the laser, users can write, erase, and rewrite data as needed.

In contrast, the other methods mentioned do not apply to DVD-RW and DVD+RW technology. The dye-changing method typically refers to earlier write-once DVD formats and isn't relevant for the rewritable type. The magnetic-changing method is associated with magnetic storage technologies like hard drives rather than optical discs. The term "standard recording method" lacks specificity and does not denote a recognized technique in the context of rewritable DVDs.