Over the past two decades, full-waveform inversion (FWI) has advanced rapidly in the seismic industry, addressing both technical and business challenges in the upstream sector. This technology offers enhanced subsurface information from seismic data. Recently, there has been a growing focus on incorporating elastic physics into waveform inversion, as originally formulated by Tarantola, to tackle complex subsurface issues. Elastic full-waveform inversion (EFWI) is emerging as a pivotal area in exploration seismology, aiming to maximize the value of seismic data for various applications, including exploration, production, and geophysical engineering.