3.25 describe how digital signals can carry more information

Quantisation

Quantisation is the process of rounding multiple values in a signal to a smaller set. This means more information can be packed into a smaller space.
With digital signals very little information is lost but with analogue a lot of information is lost.

The red line is the original signals and the black line is after it's been quantisised. As you can see a lot of information is lost when this occurs.
With digital signals more information can be packed in and less information is lost.

Multiplexing

Many digital signals can be sent down 1 wire with little interference. On the other hand analogue signals receive large amounts of interference so cannot be sent down the same wire.