Two-way satellite Internet uses Internet Protocol (IP) multicasting technology, which means up to 5,000 channels of communication can simultaneously be served by a single satellite. IP multicasting sends data from one point to many points (at the same time) by sending data in compressed format.
Compression reduces the size of the data and the bandwidth. Usual dial-up land-based terrestrial systems have bandwidth limitations that prevent multicasting of this magnitude.
Some satellite-Internet service still requires you to have a dial-up or cable modem connection for the data you send to the Internet. The satellite data downlink is just like the usual terrestrial link, except the satellite transmits the data to your computer via the same dish that would allow you to receive a Pay-Per-View television program.
So, if you are in a rural area and you want broadband access to the Internet, satellite Internet may be for you!