Inversion is a research area in geophysics that focuses on studying the subsurface structure of the Earth by analyzing physical measurements collected at the surface. This involves the use of mathematical and computational algorithms to interpret geophysical data, such as seismic waves, gravity measurements, and electromagnetic signals, in order to create a model of the subsurface. Inversion techniques can provide valuable information about the composition, density, and geometry of geological formations, and are commonly used in mineral exploration, oil and gas exploration, and earthquake studies.