This chapter presents a general concept and important parameter of grounding systems, such as grounding impedance. A grounding impedance is dependent on ground resistance and especially on the impedance of the conductor that connects buried grounding electrode(s) with radio equipment. Different grounding configurations, such as single point and multipoint groundings, are considered here. Dependent on frequencies, grounding systems are classified into low-frequency and high-frequency grounding, which are considered separately in this chapter. Low-frequency grounding is more associated with safety AC and lightning grounding, while high-frequency grounding is associated with RF grounding. Additionally, both types of groundings are considered for multistory building in this chapter. Critical points of safety grounding for multistory buildings is large grounding conductor loops, which should be avoided by planning the multistory grounding. Additionally, to avoid long grounding conductors for multistory applications, local RF groundings, which are placed directly underneath high-frequency equipment in the building, is described as well in this chapter.