Danny Sullivan, the Google Search Liaison, gave a good analogy of the differences between ranking systems, ranking signals and ranking factors. He said signals and factors are the same, the “signal/factors are like fuel; systems are the machine that uses them,” Sullivan wrote.

Danny Sullivan explained that at Google, “We use signal and factor fairly synonymously.”

He said that the signals and factors “are indeed different from systems that tend to process signals/factors.” He said think of these “as fuel and a machine.”

Where the “signal and factors are like fuel” while the “systems are the machine that uses them.”

Here is that post:

I like the analogy; I think it works.

Forum discussion at X.