Starcraft 2 (SC2) is a military science fiction real time strategy (RTS) developed and published by Blizzard Entertainment and released in 2010 for PC. It features both single-player modes along with multiplayer modes. It is the sequel to the Starcraft 1 and its expansion from 1998. The game revolves around the same three species as the original which are Terrain (humans), Protoss (advanced humanoid aliens with no mouths) and Zerg (bug-like aliens similar to Starship Troopers). The game also continues its story and campaign a few years after the original with some of the old characters with the addition of new ones.
SC2 also has 2 expansions after the base game Wings of Liberty in which you play as the humans in the campaign. Heart of the Swarm being the first expansion which adds a playable zerg campaign and continues the story further. The second being Legacy of The Void which adds a playable protoss campaign and continues the story further and then concludes it.
Since then Blizzard has made a lot of updates and changes to the game as well as adding more game modes like arcade and coop mode through online patches.
Engine
Blizzard created their own homemade engine for developing SC2 and later added their own editor tool that was capable of creating mods, maps and campaigns. It later got upgraded in phase 2 and now can be used for creating different game genres like RPG’S, FPS’s, etc.