Monte Carlo simulation is a computerized mathematical technique that allows people to account for risk in quantitative analysis and decision making. The technique is used by professionals in such widely disparate fields as finance, project management, energy, manufacturing, engineering, research and development, insurance, oil & gas, transportation, and the environment.
It is a technique implemented on excel sheets by making tables and analyzing data.
Monte Carlo analysis lets you simulate many data sets, analyze each, and then look at the distribution of parameters (results) of those analyses. This can let you "experiment" with alternative experimental designs via computer before you collect any data. Prism makes it easy, without requiring any programming or scripting.