Probabilistic Seismic Hazard Analysis (PSHA) is a practical framework, with a sound theoretical basis, used globally for assessing seismic hazard at different spatial scales to suit many different objectives. Soon after its establishment in the late 1960s, communities involved in PSHA for national seismic hazard mapping and for the siting and design of nuclear facilities led the development of this scientific-technical discipline. In recent years, other scientific and commercial sectors introduced specialised modelling approaches such as the ones shaped by the community serving the financial sector and, most recently, the research groups involved in infrastructure and man-made earthquake hazard and risk analysis.