CDs and DVDs can be used to preserve data and digital files. CDs and DVDs are laser discs and provide a great way for one to store a multi-media project. CDs and DVDs have limited amounts of space so many times multiple CDs or DVDs must be used. But, CDs and DVDs provide a portible way to transport files from one machine to another. Files can be easily saved and accessed after use. But, CDs and DVDs have a limited life span. These disks can become scratched easily and data can be unreadable. If this happens data can be lost.
For more information please see the Wikipedia article: