At the risk of some oversimplification, I think there have been two basic types of economic crisis. The old-style economic crisis I will call Type I, and the new-style, which has come to prominence over the past decade, I will call Type II. Most of these crises occur in developing countries, but developed ones have not been immune from them.
The standard way that countries -- particularly developing countries -- got into trouble in the past was that their governments did the wrong thing by running bad fiscal and monetary policy. Governments ran large budget deficits and did not finance them properly -- they wrote cheques on the central bank, which is colloquially known as printing money.