When we talk about the Internet we imagine one system that is a load
of wires encompassing the world. In fact there are several systems that
all interact to make up the Internet. The networks that can carry this
information are:
Fixed Telephone network (both conventional and fibre optic)
Mobile Telephone network
Cable Television network (the information superhighway)
Terrestial Digital Television
When people talk about "convergence" then they are talking
about one of these networks coming to dominate and all of our information
will come through one of them - for my money it will be the fixed phone
network (because virtually everyone has it, whereas all the other systems
require people to get new harware).