Mobile devices are a combination of hardware, operating system, networking, and software.

		Hardware includes PDA's like Palm Pilot or Handspring, mobile phones, and video game players.
		Operating systems tell the mobile device how to work. There are currently many competing operating systems without a clear market leader.
		Networks are the infrastructure that supports the transfer of information. the current mobile network is your local cell technology.
		Applications are the programs like phone books and calendar programs