Though Blizzard Entertainment released StarCraft as a finalized product, like many other games, it was far from perfect. Numerous exploits, glitches, and bugs were discovered but subsequently repaired by the release of patches. Whenever a patch is released, it attempts to fix errors in the game but also adds implementations for the betterment of gameplay or user interface. Each patch released signifies a newer version of StarCraft, and they are available either through Blizzard's Official Site, Battle.net's gaming service, or third party hosting sites.
StarCraft's latest and current version is 1.21.4.
Below is a list of versions and the changes they implemented.