Geostatistical techniques create surfaces incorporating the statistical properties of the measured data. Because geostatistics is based on statistics, these techniques produce not only prediction surfaces but also error or uncertainty surfaces, giving an indication of how good the predictions are.
Background: Geostatistics, in its original usage, referred to statistics of the "earth" such as in geography and geology. Now in spatial statistics, geostatistics was synonymous with "kriging", which is a statistical vrsion of interpolation.
Note: Geostatistics relies on both statistical and mathematical methods, which can be used to create surfaces and assess the uncertainty of the predictions. While the deterministic techniques only use mathematical functions for interpolation, and cannot assess the prediction.