We can measure the electrical resistance of almost anything, including soil. Understanding the resistance to electricity that the soil provides enables engineers to draft and design grounding systems to meet engineering specifications. The difference between resistance and resistivity is relatively simple. Resistivity is resistance placed in terms of weight or volume, such as, “the resistance of a pound of copper” or “the resistance of a gallon of water.” In the case of soil, we want to measure a particular volume, typically a cubic meter. So, the resistivity of soil is given in ohmmeters.