Demo disk
A physical diskette or CD (compact disc) used to help demonstrate a service, program, software utility, or software game. A demo disc or demo disks offer a free or cheap way for a user to try a program before buying it or signing up. The picture shows an AOL (America Online) demo disc to try AOL for 1,000 free hours. So many of these discs were received that they were often called coasters.
Demo disks and demo discs were replaced by downloadable demos from the Internet.
A demo disk may also refer to a diskette or disc with multiple demos. For example, many computer magazines and books send demo disks packed full of demos. These disks can be very nice as they allow users not need to download several hundred megabytes of demos from the Internet.