Common Turkic or Shaz Turkic is a taxon in some of the classifications of the Turkic languages, which in Lars Johanson proposal contain the following subgroups:
In that classification scheme, Common Turkic is opposed to Oghur Turkic (Lir-Turkic). The Common Turkic languages are characterized by sound correspondences such as Common Turkic ลก versus Oghuric l and Common Turkic z versus Oghuric r.
In other classification schemes (such as Alexander Samoylovich and Nikolay Baskakov), the breakdown is different.
References
Common Turkic languages Wikipedia(Text) CC BY-SA