Describe how digital signals can carry more information.

Digital signals are capable of carrying more information
than analogue signals because digital signals make use of the bandwidth more efficiently
by closely approximating the original analogue signal.  The parts of the signal that do
not carry any information are thrown out thus saving the bandwidth from being used
needlessly.  Also, depending on the coding process, digital signals are much more
efficient at filtering out noise than are analogue signals, which do not filter out
noise at all thus saving even more bandwidth.  The process of approximating the analogue
signal in digital signal processing is called quantization.