What is the difference between a “ground” and a “signal return”?

EMC guru Kenneth Wyatt’s writes:

"So many product designers still believe "ground" is some sort of "sink hole" for noise to drain into. I would propose we in the EMC and design communities delete the word "ground" from our vocabularies and replace with signal return and power return. Likewise, replace "ground plane" with return plane. It is much more descriptive of the actual physics. Remember all currents flow in loops - including "noise" currents! Defining return paths for all currents, while minimizing the (current) loop areas would go far in reducing EMI and resulting PC board spins. Companies whose designers understand this will end up far ahead of their competitors! I highly recommend watching these free video presentations."

Brush up on your EMC basics or learn from current industry leaders whenever and wherever you want – watch these FREE, online presentations on radiated emissions (RE), shielding, EMI filters, and grounding. Discover how to successfully design and evaluate your electronic product or system to meet EMC requirements.

This tutorial is an overview of many of the major topics that need to be considered when designing an electronic product or system to meet EMI/EMC requirements. The tutorial will present the foundational ideas from physics and mathematics and will demonstrate the engineering approaches to help the attendees to be able successfully design, evaluate, diagnose, and/or solve EMI/EMC problems. The main objective of this tutorial is to provide a learning opportunity for those that are new to EMC/EMI as well as provide a review of the basics to those who already have experience in this area. Topics included in the Tutorial are emissions, printed circuit boards, grounding, shielding, cables, filters and testing fundamentals.

http://bit.ly/2haDYJR