Satellites in orbit above the earth are invaluable for long-distance communication, and some support providing an internet connection. For those really going off grid away from cellular towers and Wi-Fi, satellite internet is a great option.
Satellite internet requires two-way communication between a receiver on the earth and the satellite in orbit - which requires very precise aiming. Mobility for RV and marine use gets complicated with finding a provider who supports and large bulky equipment installation. And because of the distance of the satellite in orbit, latency tends to be quite high.
While possible now, mobile satellite internet is aiming to get a lot more interesting in future years as lower earth orbit options are launching by Space-X, OneWeb and Project Kuiper.