It is also used as a means of copy protection – you cannot start single-player or multi-player games without the CD (but can join multi-player games started by others). Unlike Warcraft, there is no “full install” option, and a lot of the data, including the videos and campaign narrations, is kept on the CD you need to have either the original or the expansion CD in the drive, depending on which campaign you want to play.
These are not actually the newest versions – there are patches out there to update 1.22 to 1.4, and 1.33 to 1.5 the only meaningful difference, according to official documentation, is a fix that prevents certain kinds of in-memory cheating in multiplayer games. The Beyond the Dark Portal expansion CD can only be installed on top of an existing Warcraft II installation it installs all the expansion-specific missions and characters and updates the program to version 1.33, which can run both the original and the expansion campaigns. The Warcraft II CD installs version 1.22, which is the final Tides of Darkness version before the expansion. The Mac version also has improved, higher-resolution graphics. The CD does have nice audio tracks, but these only play in the Mac version it’s a shame the DOS version never got this feature.
When installing from the CD, you can opt for a full install, which will copy all data to the hard drive, and then the CD is not required (there is no copy protection).
It has nice extras over the floppy version – small animated 3D maps and full audio narration before every campaign mission, plus a few bug fixes.
Warcraft installs the CD version 1.22h, which is the final official release.