keberoxu wrote: (I don't know why it's called "optical.")

Optical drives use light - from a laser - to write and read information from a spinning disk. There was a early type called 'laserdiscs' * which were used to distribute video recordings. Optical drives were also used for high-volume data storage: one popular consumer type was the 'zip drive'. CDs and DVDs use the same technology and an 'optical drive' generally means one that will read and write those, for both ordinary music and video, and data storage (of which there are numerous types, called CD-something and DVD-something).

*I was looking recently for a DVD of Götterdämmerung by Barenboim at Bayreuth, and I found a laser disc version selling for about £10, much cheaper than the DVD. A second-hand player would cost me several hundred pounds though.