Low frequencies are critical for the success of full-wave inversion (FWI). With the point-receiver marine and land acquisition system, low frequencies are significantly improved compared with conventional surveys. For marine data, the lowest frequency band that can be used for FWI is 2-3 Hz. For land data, the lowest frequency band that we can use for FWI is 2-4 Hz. Wide-azimuth (WAZ) acquisition facilitates FWI by highly improved data coverage with a higher signal-to-noise (S/N) ratio, better illumination, and longer offset. FWI was successfully carried out with both marine and land data sets from low to high-frequency bands. The final FWI velocity models were validated by both Kirchhoff depth migration and reverse-time migration (RTM).