From Liquipedia Starcraft Wiki
Cheese is a pejorative expression which refers to a strategy that is highly unconventional and designed to take one's opponent by surprise. In general, cheese is hard to beat if not scouted but easy to defeat if it is scouted.
- Proxy-Gateways: Placing your first Pylon and Gateway(s) near the opponent's base, trying to win the game quickly by Zealots only.
- 4/5-Pool: Sacrificing Economy, placing an early Spawning Pool to produce a set of 6/8 Zerglings to overrun the enemy.
- BBS: Building two Barracks, preferably near the enemy's base, before placing the first supply depot.
They can be more complex, however, such as proxying Starports, Robotics Facilities, and many more. If a build order classified as Cheese fails, the player using it will usually be far behind in the game. Finally, the usage of the term is often restricted to the victim of the "cheesy" strategy, to play down the opponent's achievement.
 Exemplary Games:
 Supposed Origins
During a broadcast game on September 16, 2009, OGN commentator Um Jae Kyung (엄재경) briefly discussed the difference between a bunker rush and a "cheese" rush. According to his explanation, the term "cheese" originated from the word "cheater's" (words in Korean are sometimes shortened by the middle syllables, so 치터즈 [chi tuh zu] would become 치즈 [chi zu]). The strategy is characterized by, as opposed to a simple bunker rush, a practically unbeatable combination of most of the Terran's SCVs and a very quickly assembled group of marines. Because both Protoss and Zerg basic units are unranged, SCVs can effectively prevent the ranged marines from being destroyed by obstructing the path between the units, giving the marines a tremendous (and thus unfair) edge.
The usage of the term "cheese" has expanded to include most "all-in" strategies which involve a great sacrifice of economy, though some StarCraft communities use the term even more loosely to include mid-game strategies.