Apple Macs and other types of computers can be networked together and can happily share a modem.
You can share a USB modem internet to other computers on the network by simply creating a wireless network with the comp where the modem is connected and then connecting the other computers to the network via the wireless network that you created.
modem
Apple does not allow other companies to manufacture apple compatible computers. Some, such as Psystar, have tried but have been taken to court and forced to stop.
Wi-Fi Modem.
Providing the PC has been made by Apple then it is possible to load OS X. The legal agreement you accept when installing OS X does not allow it to be installed on computers made by a company other than Apple.
You should have your modem wired to at least one of your computers. If you have a desktop you should attach the modem to that so that it can send out the ISP to the other computers. It is necessary for you to do this, that way any other computer you use will have no problem picking up the signal and using the ISP.
Modem is an acronym for modulator-demodulator. It is a device which makes communication between computers and other devices possible by converting data to a form which the phone or cable lines can transmit.
MODEM (Modulator - Demodulator) allows communication between computers.Generally Modem connects to ISP over analog telephone line and further ISP connects to Computers over Internet.
Apple computers are made by Apple. Apple write their own operating system called Mac OS X to use on their computers. Legally you can only run Mac OS X on a computer made by Apple. Other makes of computer cannot be turned into Apple computers.
The computer was not invented by Apple. They tried to fill a market of personal computers using different software and hardware then other computers.
You can "facetime" other apple computers, or use Skype.
The device allowing two computers to communicate with each other is... a router (or modem).