There are a *very few* phones and computer communications devices that are satellite based. They are very high powered, and unless you're going to be wandering around in the middle of nowhere, just a waste of perfectly good money.
As far as the vast majority of cell phone systems and computer communications go, satellites aren't involved.
Cell phones will hit reception towers, which will near-instantaneously decide between them which one will handle the call. Your call is then routed directly to a land line. If you're calling an office, store, home, and so on, the land line will take your cell call directly there. If you're trying to reach another cell phone, the land line will direct your call to the nearest transmission tower, at which point you can talk to your girlfriend. That's right... 90% of your magical cell phone call takes place on a land line. They do not connect with satellites unless you're making a call over a long distance, like Los Angeles to New York City, in which case your signal will be bounced from a standard land line transmission tower up to the satellite, and then back down to a standard reception tower, then routed back out to the cell network (if you're trying to reach another cell phone, otherwise, again, it just sticks to the land line). It's for this reason that if you're in the middle of isolate Okahoma, standing ten feet away from your lover, you cannot make a cell call to her, because the calls have to be properly routed through reception and transmission towers, not directly phone-to-phone.
Computers use short-range radio technology to interface with various types of networks, which an be to your DSL router, your printer, or even your girlfriend's computer on the other side of the room. However, these home networks rarely work over a hundred feet or so, as signal strength simply degrades beyond use. The wireless Internet is basically like a cell phone - your computer transmits a very short distance to a receiver, which directly routs you to a land line, be it a DSL or Cable connection. There's no satellite involved, though again, if you really need to blow money, battery power, and play Halo 3 from the middle of the Yukon, there are a very few computer-based satellite communications devices.
Not always Depends on the type of network that is being used.If U are using a wired internet connection it will be getting messages from the exchange to which you are connected. But the exchange may be using a microwave links or satellite links. Cell phones use wireless connections with a number of cells spread all around a city and the connection gets transferred from one cell to another as you move around. Certain types of cellphones may have direct connectivity to satellites.