Arab vs Arabic

"As adjectives, the New Oxford American Dictionary defines Arabic a related to the language or the literature, while Arab is the more generic term (“of or relating to Arabia and the people of Arabia”) and Arabian is a historical variant of Arab."

also
"Arabs are a people whose place of ethnic origin is the Arabian Peninsula.

The language which they speak, and which has spread widely to other areas, is Arabic. “Arabic” is not generally used as an adjective except when referring to the language or in a few traditional phrases such as “gum arabic” and “arabic numerals.” Note that in these few phrases the word is not capitalized. Otherwise it is “Arab customs,” “Arab groups,” “Arab countries,” etc."

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Note added at 12 hrs (2019-10-30 12:34:29 GMT)
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I also found this in a language forum:

"As an Arab, I feel quite strongly about this. Let me tell you how I use and like those around me to use the terms. :) These may or may not be dictionary definitions!

Use "Arabic" only when referring to the language. "Arabic culture" and "Arabic countries" sound awful to my ears. I might be able to stomach "Arabic music" because I can see a reference to the language - but generally, use "Arabic" only in phrases like "Arabic syntax," "Arabic grammar," "Arabic literature," etc.

In all other modern adjectival instances, use "Arab": "Arab culture," "Arab countries," "Arab politics," "Arab hospitality," "Arab history," "Arab relations with the West," etc.

Please do not use "Arabian" unless you are talking about horses, knights, or 1001 nights!! "