A plastic disc with a thin layer upon the "top" layer to which data is recorded by a CD-R or CD-RW drive that doubles as a label.
The label is, in almost all cases, incapable of being written upon except by a Sharpie and few other felt-tip pens which are uncommon to all mankind.
The plastic disc itself also doubles as a dirt and scratch magnet, making it almost unreadable within one to two months.
The common CD-R is seen and sold without any kind of protection. They are sold en masse most commonly in ammounts of 25, 50 and 100 discs at a time.
CD-Rs originally were able to contain a volume of 74 minutes of CDA or 650 megabytes of data. Newer (and the most common) CD-Rs now are able to store 80 minutes of audio data, and a round 700 megabytes of files.
Guy 1: You can't be seriously bailing on us..
Guy 2: The CDR is HUuuuuuuuuge.
Guy 1: Oh.. Ohhhhh!! Well then.. have fun dude!
Guy 1: This party is gonna be hella gay..
Guy 2: Why? I think it's gonna be fuckin sick.
Guy 1: Well, the host decided it would be a great idea to keep the CDR reaaaaal low.. It's gonna be a sausage fest.
Guy 2: Bummer...