Ethnically, they are a mix of early Turkic and Mongol tribes. Persian, Russian and in smaller degree Arab cultures influenced the current Kazakh traditions.
The Kazakh language is close to other Turkic languages. Native speakers of Kazakh, Uzbek, Kyrgyz, Tatar, Uighur can easily communicate without the need for a translator; Turkish, Azeri, Turkmen can easily be picked up - due to the close similarity - for example: "al" means "take" in Kazakh, but it means the same thing in almost any Turkic language. The same goes for "at" - "horse", "otir(otur)" - "sit" etc.
The Kazhaks form one of the 56 ethnic groups officially recognized by the People's Republic of China.