What is digital Termination and when is it used?
Digital termination is the same thing as transmission line termination. It's just a nuance that indicates that the goal is to reduce reflections of fast edges rather than match a specific impedance per se, although in reality, they're the same thing.

There are a number of ways to terminate a digital line. If a digital driver has lower impedance than the line impedance, you'll often see a series resistor to make up the difference. On the other hand, digital receivers usually have an input impedance that's higher than the line impedance, so a shunt resistor (AKA "parallel termination") is used.

When using parallel termination, the other end of the resistor is attached to a voltage source. This can be ground, Vcc, or some other voltage in between (in which case, two resistors are used as a voltage divider to create the equivalent Th&eacute;venin voltage and resistance).

What you have is an example of parallel termination to ground.