Dialects are distinguished on the basis of isoglosses. However, the distribution of different distinguishing features of dialects do not always overlap.
The primary dialectal isogloss has a name in Arabic that is pronounced in accordance with the speaker's dialect: قال وقلنا. This isogloss is the first basis for the distinction between Urban dialects, Rural dialects, Bedouin dialects & Druze dialects.
Other isoglosses highlight a distinction between one variety versus the others.
The second primary isogloss is less sociolectal & more geographic, marking a transition from the southern varieties of Levantine Arabic to the northern ones; this is the pronounciation of ة.
A third isogloss of unclear distribution is the quality of the close vowel (either /i/ or /u/) in certain CvCC terms. It is not clear to what extent the pronunciation of all such terms is linked — if at all — or whether this is feature linked to the pronunciation of other terms like باكل vs. بوكل.