Power ground is common in almost all audio electronics. However, signal ground is often ignored or overlooked by audiophiles and less experienced dealerships.
Analog music signals pass through zero as they travel from positive to negative, similar to a sine wave in basic physics or trigonometry classes. The issue arises in how the zero point is established from one piece of equipment to another. Most simply attach to some point in the power circuit. Where it is placed is important and varies by manufacturer.
Enklein grounding cables establish a common signal ground between all your electronics, creating continuity and enhancing the audio and video experience.