Hardware or Conduits - the digital paths

Traditional - dial up, dedicated or leased lines
Telephone companies - AT&T, Sprint
Regional network providers - NYSERnet, CERFnet, etc.
CATV/IP - not 500 channels, just a 10Mb line to your home
Wireless - packet radio, personal communication systems
Satellite - VSAT, other
Other - Electric Power Company, or Railroad right of way