I will assume you have good reasons to continue re-posting the almost exact same question over the course of 5 years (that is impressive!), but after reading a couple of the duplicates, I am left wondering, why?
I see you tried asking about:
- The linguistic difference between 'differential' and 'difference' as an adjective. You received very good answers there explaining what 'differential pricing' is and why 'different pricing' is not the same.
- Then you ask about the difference between 'differential' and 'difference' as a noun, using the exact same text and simply highlighting a noun ('price differentials'). But, you don't link to your previous question or explain why the answers you got there don't help you!
It is also worth noting that all these questions seem to start from the assumption that synonymous words should carry the exact same meaning ("ODO doesn't distinguish them"). This is not the case, which interestingly was a question we got on this site recently: Is there such a thing as word synonyms?
But, you should have already known that in 2015 since you got somebody pointing this out to you:
The definitions for "different" are quite different from the definitions for "differential".
Now you come here, and ask about the difference of 'differential' and 'difference' in Psychology handbooks. But, again, you make no effort of linking to your past questions, or clarifying why the answers there do not answer your question! This is why your question got rightfully closed, and Arnon was right in giving you a warning. I would be interested in hearing any motivation you have for not making your question more clear or specific if your intent is to learn.
Concretely, why does the answer you got last year not answer the question that got deleted?
Also, aside from the dictionary definitions, "differential" is commonly used in a lot of technical jargon where "difference" or "different" wouldn't work. "Differential equations", "differential steering", and "differential pricing" cannot be replaced with "different equations" etc. In these cases, "differential" describes a system that relies on or is related to differences; it doesn't just mean "different".