Counter-Strike: Source (CSS) is a game from the Counter-Strike series which emerged originally as a Halflife`s mod. Like it's predecesors, is a FPS (First Person Shooter) game, released in late 2004. The main difference is that this third part of Couterstrike series, uses Half Life's 2 engine known as "Source" which is more powerful and has Havoc's physic options, allowing better graphics and more realistic efects.
Another difference, is that this new Counterstrike works only under "STEAM", so the game will not play unless a STEAM account is created, and in order to create an account, the user must own a valid CDKey. There is here need to mention that the game's maintenance is compleetely free.
The game is a whole success itself, it began as an experiment in which the people of valve wanted to show how easy was to use Half life's source and turn it into a whole new experience.
As a long-time-fan from the original Counter-Strike, I was one of the first persons in line when it came to the stores. And I can tell you that this new version is really worth every buck paid. If you are a person who likes the FPS online, this is a really good option to spend many hours taking advantage of your DSL/Cable connection.