Alternatively referred to as a disc drive, optical media, optical storage, Optical disc drive, and optical disk, an optical disc is any media read using a laser assembly. The most common types of optical media are Blu-ray, CDs, and DVDs. Computers can read and write to CDs and DVDs using a CD writer or DVD writer drive, and a Blu-ray is read with a Blu-ray drive. Drives such as a CD-R and DVD-R drive that can read and write information to discs are known as MO (magneto-optic).
There are three main types of optical media: CD, DVD, and Blu-ray disc. CDs can store up to 700 megabytes (MB) of data and DVDs can store up to 8.4 GB of data. Blu-ray discs, which are the newest type of optical media, can store up to 50 GB of data. This storage capacity is a clear advantage over the floppy disk storage media (a magnetic media), which only has a capacity of 1.44 MB. Another advantage that optical media have over the floppy disk is that it can last up to 7 times longer, due to its improved durability.
A CD drive can only read CD discs, a DVD drive can only read DVD and CD discs, and a Blu-ray drive can read CD, DVD, and Blu-ray discs.
Because these discs are read by light (optical) they should be referred to as an optical disc, not optical disk.