CDs are compact discs.  They are a popular format for storing music.  They are used primarily by the music industry to sell CDs from musicians but have been used as storage space before DVDs became the standard for that.  CDs can generally hold less than 1 GB of data, but they can hold just about any type of media, data and information out there.  They can be burned to and from, and they come in both writeable and re-writeable formats.

DVDs are digital video discs and have replaced CDs as the primary way to burn and back up media, documents and more. DVDs are also the standard for movie to be sold and distributed around the world. DVDs can hold up to 5 GB of data in most cases, and they also come in writeable and re-writeable formats. Most computers come with built-in DVD burners and readers on today's market.

CDs, DVDs and now Blu Ray have become the standard types of media on the market. While most computers come with DVD burners, many manufacturers are beginning to release models with Blu Ray players built-in. In the near future, it will be possible for the average consumer to burn and play Blu Ray DVDs on both their computers and in their home theater systems. For now, only those with enough money can invest in Blu Ray burning.

Older computer users still rely on floppy disks, Zip disks and CDs for storage and media solutions.  Many computers can be hooked up to floppy disk readers or Zip drive readers and since they come with DVD burners, they can play and burn CDs as well.  While these may well be phased out over time, every consumer finds the best way to store media and backup their data even if it is outdated on the market to the rest of us.